Edgar Filing: CYTOKINETICS INC

	UNITED STATES
	SECURITIES AND EXCHANGE COMMISSION
	Washington, D.C. 20549

	SCHEDULE 13G (Rule 13d-102)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1 (b), (c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO 13d-2 (b)

Under the Securities Exchange Act of 1934
(Amendment No. )*

Cytokinetics, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

23282W100

(CUSIP Number)

December 31, 2004

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

o	Rule 13d-1(b)
o	Rule 13d-1(c)
ý	Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 23282W100

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Sevin Rosen Fund VI L.P. (“SR VI”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization Delaware

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 1,615,715 shares, except that SRB Associates VI L.P. (“SRB VI”), the general partner of SR VI, may be deemed to have sole power to vote these shares, and Jon W. Bayless (“Bayless”), Stephen M. Domenik (“Domenik”) Stephen M. Dow (“Dow”), John V. Jaggers (“Jaggers”), and Charles H. Phipps (“Phipps”), the general partners of SRB VI, may be deemed to have shared power to vote these shares.

			6.		Shared Voting Power See response to row 5.

			7.		Sole Dispositive Power 1,615,715 shares, except that SRB VI, the general partner of SR VI, may be deemed to have sole power to dispose of these shares, and Bayless, Domenik, Dow, Jaggers and Phipps, the general partners of SRB VI, may be deemed to have shared power to dispose of these shares.

			8.		Shared Dispositive Power See response to row 7.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,615,715

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 5.7%

	12.	Type of Reporting Person (See Instructions) PN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Sevin Rosen VI Affilitates Fund L.P. (“SR VI A”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization Delaware

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 127,235 shares, except that SRB VI, the general partner of SR VI A, may be deemed to have sole power to vote these shares, and Bayless, Domenik, Dow, Jaggers and Phipps, the general partners of SRB VI, may be deemed to have shared power to vote these shares.

			6.		Shared Voting Power See response to row 5.

			7.		Sole Dispositive Power 127,235 shares, except that SRB VI, the general partner of SR VI A, may be deemed to have sole power to dispose of these shares, and Bayless, Domenik, Dow, Jaggers and Phipps, the general partners of SRB VI, may be deemed to have shared power to dispose of these shares.

			8.		Shared Dispositive Power See response to row 7.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 127,235

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 0.4%

	12.	Type of Reporting Person (See Instructions) PN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) SRB Associates VI L.P. (“SRB VI”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization Delaware

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 1,742,950 shares, of which 1,615,715 are directly owned by SR VI and 127,235 are directly owned by SR VI A. SRB VI, the general partner of SR VI and SR VI A, may be deemed to have sole power to vote these shares, and Bayless, Domenik, Dow, Jaggers and Phipps, the general partners of SRB VI, may be deemed to have shared power to vote these shares.

			6.		Shared Voting Power See response to row 5.

			7.		Sole Dispositive Power 1,742,950 shares, of which 1,615,715 are directly owned by SR VI and 127,235 are directly owned by SR VI A. SRB VI, the general partner of SR VI and SR VI A, may be deemed to have sole power to dispose of these shares, and Bayless, Domenik, Dow, Jaggers and Phipps, the general partners of SRB VI, may be deemed to have shared power to dispose of these shares.

			8.		Shared Dispositive Power See response to row 7.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,742,950

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 6.1%

	12.	Type of Reporting Person (See Instructions) PN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Sevin Rosen Fund VII L.P. (“SR VII”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization Delaware

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 625,950 shares, except that SRB Associates VII L.P. (“SRB VII”), the general partner of SR VII, may be deemed to have sole power to vote these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Jackie Kimzey (“Kimzey”) and David Shrigley (“Shrigley”), the general partners of SRB VII, may be deemed to have shared power to vote these shares.

			6.		Shared Voting Power See response to row 5.

			7.		Sole Dispositive Power 625,950 shares, except that SRB VII, the general partner of SR VII, may be deemed to have sole power to dispose of these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey and Shrigley, the general partners of SRB VII, may be deemed to have shared power to dispose of these shares.

			8.		Shared Dispositive Power See response to row 7.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 625,950

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 2.2%

	12.	Type of Reporting Person (See Instructions) PN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Sevin Rosen VII Affiliates Fund L.P. (“SR VII A”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization Delaware

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 24,050 shares, except that SRB VII, the general partner of SR VII A, may be deemed to have sole power to vote these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey and Shrigley, the general partners of SRB VII, may be deemed to have shared power to vote these shares.

			6.		Shared Voting Power See response to row 5.

			7.		Sole Dispositive Power 24,050 shares, except that SRB VII, the general partner of SR VII A, may be deemed to have sole power to dispose of these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey and Shrigley, the general partners of SRB VII, may be deemed to have shared power to dispose of these shares.

			8.		Shared Dispositive Power See response to row 7.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 24,050

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 0.1%

	12.	Type of Reporting Person (See Instructions) PN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) SRB Associates VII L.P. (“SRB VII”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization Delaware

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 650,000 shares, of which 625,950 are directly owned by SR VII and 24,050 are directly owned by SR VII A. SRB VII, the general partner of SR VII and SR VII A, may be deemed to have sole power to vote these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey and Shrigley, the general partners of SRB VII, may be deemed to have shared power to vote these shares.

			6.		Shared Voting Power See response to row 5.

			7.		Sole Dispositive Power 650,000 shares, of which 625,950 are directly owned by SR VII and 24,050 are directly owned by SR VII A. SRB VII, the general partner of SR VII and SR VII A, may be deemed to have sole power to dispose of these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey and Shrigley, the general partners of SRB VII, may be deemed to have shared power to dispose of these shares.

			8.		Shared Dispositive Power See response to row 7.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 650,000

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 2.3%

	12.	Type of Reporting Person (See Instructions) PN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Sevin Rosen Fund VIII L.P. (“SR VIII”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization Delaware

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 755,631 shares, except that SRB Associates VIII L.P. (“SRB VIII”), the general partner of SR VIII, may be deemed to have sole power to vote these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey, Shrigley and Alan Schuele (“Schuele”), the general partners of SRB VIII, may be deemed to have shared power to vote these shares.

			6.		Shared Voting Power See response to row 5.

			7.		Sole Dispositive Power 755,631 shares, except that SRB VIII, the general partner of SR VIII, may be deemed to have sole power to dispose of these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey, Shrigley, and Schuele, the general partners of SRB VIII, may be deemed to have shared power to dispose of these shares.

			8.		Shared Dispositive Power See response to row 7.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 755,631

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 2.7%

	12.	Type of Reporting Person (See Instructions) PN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Sevin Rosen VIII Affiliates Fund L.P. (“SR VIII A”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization Delaware

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 15,421 shares, except that SRB VIII, the general partner of SR VIII A, may be deemed to have sole power to vote these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey, Shrigley and Schuele, the general partners of SRB VIII, may be deemed to have shared power to vote these shares.

			6.		Shared Voting Power See response to row 5.

			7.		Sole Dispositive Power 15,421 shares, except that SRB VIII, the general partner of SR VIII A, may be deemed to have sole power to dispose of these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey, Shrigley and Schuele, the general partners of SRB VIII, may be deemed to have shared power to dispose of these shares.

			8.		Shared Dispositive Power See response to row 7.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 15,421

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 0.1%

	12.	Type of Reporting Person (See Instructions) PN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) SRB Associates VIII L.P. (“SRB VIII”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization Delaware

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 771,052 shares, of which 755,631 are directly owned by SR VIII and 15,421 are directly owned by SR VIII A. SRB VIII, the general partner of SR VIII and SR VIII A, may be deemed to have sole power to vote these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey, Shrigley and Schuele, the general partners of SRB VIII, may be deemed to have shared power to vote these shares.

			6.		Shared Voting Power See response to row 5.

			7.		Sole Dispositive Power 771,052 shares, of which 755,631 are directly owned by SR VIII and 15,421 are directly owned by SR VIII A. SRB VIII, the general partner of SR VIII and SR VIII A, may be deemed to have sole power to dispose of these shares, and Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey, Shrigley and Schuele, the general partners of SRB VIII, may be deemed to have shared power to dispose of these shares.

			8.		Shared Dispositive Power See response to row 7.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 771,052

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 2.7%

	12.	Type of Reporting Person (See Instructions) PN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Jon W. Bayless (“Bayless”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization U.S. Citizen

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 0 shares

			6.		Shared Voting Power 3,167,692 shares, of which 1,615,715 are directly owned by SR VI, 127,235 are directly owned by SR VI A, 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by Sevin Rosen Bayless Management Company (“SRBMC”). Bayless is a general partner of SRB VI, the general partner of SR VI and SR VI A, SRB VII, the general partner of SR VII and SR VII A, SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to vote these shares.

			7.		Sole Dispositive Power 0 shares

			8.		Shared Dispositive Power 3,167,692 shares, of which 1,615,715 are directly owned by SR VI, 127,235 are directly owned by SR VI A, 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Bayless is a general partner of SRB VI, the general partner of SR VI and SR VI A, SRB VII, the general partner of SR VII and SR VII A, SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to dispose of these shares.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 3,167,692

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 11.1%

	12.	Type of Reporting Person (See Instructions) IN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Stephen L. Domenik (“Domenik”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization U.S. Citizen

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 11,000 shares

			6.		Shared Voting Power 3,167,692 shares, of which 1,615,715 are directly owned by SR VI, 127,235 are directly owned by SR VI A, 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Domenik is a general partner of SRB VI, the general partner of SR VI and SR VI A, SRB VII, the general partner of SR VII and SR VII A, SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to vote these shares.

			7.		Sole Dispositive Power 11,000 shares

			8.		Shared Dispositive Power 3,167,692 shares, of which 1,615,715 are directly owned by SR VI, 127,235 are directly owned by SR VI A, 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Domenik is a general partner of SRB VI, the general partner of SR VI and SR VI A, SRB VII, the general partner of SR VII and SR VII A, and SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to dispose of these shares.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 3,178,692

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 11.2%

	12.	Type of Reporting Person (See Instructions) IN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Stephen M. Dow (“Dow”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization U.S. Citizen

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 60,000 shares

			6.		Shared Voting Power 3,167,692 shares, of which 1,615,715 are directly owned by SR VI, 127,235 are directly owned by SR VI A, 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Dow is a general partner of SRB VI, the general partner of SR VI and SR VI A, SRB VII, the general partner of SR VII and SR VII A, and SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to vote these shares.

			7.		Sole Dispositive Power 60,000 shares

			8.		Shared Dispositive Power 3,167,692 shares, of which 1,615,715 are directly owned by SR VI, 127,235 are directly owned by SR VI A, 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Dow is a general partner of SRB VI, the general partner of SR VI and SR VI A, SRB VII, the general partner of SR VII and SR VII A, and SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to dispose of these shares.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 3,227,692

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 11.3%

	12.	Type of Reporting Person (See Instructions) IN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) John V. Jaggers (“Jaggers”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization U.S. Citizen

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 0 shares

			6.		Shared Voting Power 3,167,692 shares, of which 1,615,715 are directly owned by SR VI, 127,235 are directly owned by SR VI A, 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Jaggers is a general partner of SRB VI, the general partner of SR VI and SR VI A, SRB VII, the general partner of SR VII and SR VII A, and SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to vote these shares.

			7.		Sole Dispositive Power 0 shares

			8.		Shared Dispositive Power 3,167,692 shares, of which 1,615,715 are directly owned by SR VI, 127,235 are directly owned by SR VI A, 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Jaggers is a general partner of SRB VI, the general partner of SR VI and SR VI A, SRB VII, the general partner of SR VII and SR VII A, and SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to dispose of these shares.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 3,167,692

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 11.1%

	12.	Type of Reporting Person (See Instructions) IN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Charles H. Phipps (“Phipps”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization U.S. Citizen

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 30,000 shares

			6.		Shared Voting Power 3,167,692 shares, of which 1,615,715 are directly owned by SR VI, 127,235 are directly owned by SR VI A, 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Phipps is a general partner of SRB VI, the general partner of SR VI and SR VI A, SRB VII, the general partner of SR VII and SR VII A, and SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to vote these shares.

			7.		Sole Dispositive Power 30,000 shares

			8.		Shared Dispositive Power 3,167,692 shares, of which 1,615,715 are directly owned by SR VI, 127,235 are directly owned by SR VI A, 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Phipps is a general partner of SRB VI, the general partner of SR VI and SR VI A, SRB VII, the general partner of SR VII and SR VII A, and SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to dispose of these shares.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 3,197,692

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 11.2%

	12.	Type of Reporting Person (See Instructions) IN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Jackie R. Kimzey (“Kimzey”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization U.S. Citizen

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 10,513 shares

			6.		Shared Voting Power 1,424,742 shares, of which 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Kimzey is a general partner of SRB VII, the general partner of SR VII and SR VII A, and SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to vote these shares.

			7.		Sole Dispositive Power 10,513 shares

			8.		Shared Dispositive Power 1,424,742 shares, of which 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Kimzey is a general partner of SRB VII, the general partner of SR VII and SR VII A, and SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to dispose of these shares.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,435,255

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 5.0%

	12.	Type of Reporting Person (See Instructions) IN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) David A. Shrigley (“Shrigley”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization U.S. Citizen

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 0 shares

			6.		Shared Voting Power 1,424,742 shares, of which 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Shrigley is a general partner of SRB VII, the general partner of SR VII and SR VII A, and SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to vote these shares.

			7.		Sole Dispositive Power 0 shares

			8.		Shared Dispositive Power 1,424,742 shares, of which 625,950 are directly owned by SR VII, 24,050 are directly owned by SR VII A, 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Shrigley is a general partner of SRB VII, the general partner of SR VII and SR VII A, and SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to dispose of these shares.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 1,424,742

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 5.0%

	12.	Type of Reporting Person (See Instructions) IN

	1.	Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) Alan R. Schuele (“Schuele”) Tax ID Number:

	2.	Check the Appropriate Box if a Member of a Group (See Instructions)
		(a)		o
		(b)		ý

	3.	SEC Use Only

	4.	Citizenship or Place of Organization U.S. Citizen

Number of Shares Beneficially Owned by Each Reporting Person With			5.		Sole Voting Power 0 shares

			6.		Shared Voting Power 774,742 shares, of which 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Schuele is a general partner of SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to vote these shares.

			7.		Sole Dispositive Power 0 shares

			8.		Shared Dispositive Power 774,742 shares, of which 755,631 are directly owned by SR VIII, 15,421 are directly owned by SR VIII A and 3,690 are directly owned by SRBMC. Schuele is a general partner of SRB VIII, the general partner of SR VIII and SR VIII A, and a director of SRBMC, and may be deemed to have shared power to dispose of these shares.

	9.	Aggregate Amount Beneficially Owned by Each Reporting Person 774,742

	10.	Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) o

	11.	Percent of Class Represented by Amount in Row (9) 2.7%

	12.	Type of Reporting Person (See Instructions) IN

Item 1.
	(a)	Name of Issuer Cytokinetics, Inc.
	(b)	Address of Issuer’s Principal Executive Offices Cytokinetics, Inc 280 East Grand Avenue South San Francisco, California 94080

Item 2.
	(a)	Name of Person Filing This Statement is filed by Sevin Rosen Fund VI L.P., a Delaware limited partnership (“SR VI”); Sevin Rosen VI Affiliates Fund L.P., a Delaware limited partnership (“SR VI A”); SRB Associates VI L.P., a Delaware limited partnership (“SRB VI”); Sevin Rosen Fund VII L.P., a Delaware limited partnership (“SR VII”); Sevin Rosen VII Affiliates Fund L.P., a Delaware limited partnership (“SR VII A”); SRB Associates VII L.P., a Delaware limited partnership (“SRB VII”); Sevin Rosen Fund VIII L.P., a Delaware limited partnership (“SR VIII”); Sevin Rosen VIII Affiliates Fund L.P., a Delaware limited partnership (“SR VIII A”); SRB Associates VIII L.P., a Delaware limited partnership (“SRB VIII”); Jon W. Bayless (“Bayless”); Stephen L. Domenik (“Domenik”); Stephen M. Dow (“Dow”); John V. Jaggers (“Jaggers”); Charles H. Phipps (“Phipps”); Jackie R. Kimzey (“Kimzey”); David A. Shrigley (“Shrigley”); and Alan R. Schuele (“Schuele”). The foregoing entities and individuals are collectively referred to as the “Reporting Persons.” SRB VI, the general partner of SR VI and SR VI A, may be deemed to have sole power to vote and sole power to dispose of shares of the issuer directly owned by SR VI and SR VI A. Bayless, Domenik, Dow, Jaggers and Phipps are general partners of SRB VI and may be deemed to have shared power to vote and shared power to dispose of shares of the issuer directly owned by SR VI and SR VI A. SRB VII, the general partner of SR VII and SR VII A, may be deemed to have sole power to vote and sole power to dispose of shares of the issuer directly owned by SR VII and SR VII A. Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey, and Shrigley are general partners of SRB VII and may be deemed to have shared power to vote and shared power to dispose of shares of the issuer directly owned by SR VII and SR VII A. SRB VIII, the general partner of SR VIII and SR VIII A, may be deemed to have sole power to vote and sole power to dispose of shares of the issuer directly owned by SR VIII and SR VIII A. Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey, Shrigley and Schuele are general partners of SRB VIII and may be deemed to have shared power to vote and shared power to dispose of shares of the issuer directly owned by SR VIII and SR VIII A.

	(b)	Address of Principal Business Office or, if none, Residence The address for each of the Reporting Persons is: Sevin Rosen Funds Two Galleria Tower 13455 Noel Rd. Suite 1670 Dallas, Texas 75240
	(c)	Citizenship SR VI, SR VI A, SRB VI, SR VII, SR VII A, SRB VII, SR VIII, SR VIII A and SRB VIII are Delaware limited partnerships. Bayless, Domenik, Dow, Jaggers, Phipps, Kimzey, Shrigley and Schuele are United States citizens.
	(d)	Title of Class of Securities Common Stock
	(e)	CUSIP Number 23282W100

Item 3.	If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
	(a)	o	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).
	(b)	o	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).
	(c)	o	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).
	(d)	o	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C 80a-8).
	(e)	o	An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E);
	(f)	o	An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F);
	(g)	o	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
	(h)	o	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
	(i)	o	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
	(j)	o	Group, in accordance with §240.13d-1(b)(1)(ii)(J).
	Not Applicable

Item 4.	Ownership
Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.
	(a)	Amount beneficially owned: See Row 9 of cover page for each Reporting Person.
	(b)	Percent of class: See Row 11 of cover page for each Reporting Person.
	(c)	Number of shares as to which the person has:
		(i)	Sole power to vote or to direct the vote See Row 5 of cover page for each Reporting Person.
		(ii)	Shared power to vote or to direct the vote See Row 6 of cover page for each Reporting Person.
		(iii)	Sole power to dispose or to direct the disposition of See Row 7 of cover page for each Reporting Person.
		(iv)	Shared power to dispose or to direct the disposition of See Row 8 of cover page for each Reporting Person.

Item 5.	Ownership of Five Percent or Less of a Class
If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following o.
Not applicable.

Item 6.	Ownership of More than Five Percent on Behalf of Another Person
	Under certain circumstances set forth in the limited partnership agreements of SR VI, SR VI A, SRB VI, SR VII, SR VII A, SRB VII, SR VIII, SR VIII A and SRB VIII, the general and limited partners or stockholders, as the case may be, of each of such entities may be deemed to have the right to receive dividends from, or the proceeds from, the sale of shares of the issuer owned by each such entity of which they are a partner or stockholder.

Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person
	Not applicable.

Item 8.	Identification and Classification of Members of the Group
	Not applicable.

Item 9.	Notice of Dissolution of Group
	Not applicable.

Item 10.	Certification
	Not applicable.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: February 11, 2005

SEVIN ROSEN FUND VI L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VI L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner

SEVIN ROSEN VI AFFILIATES FUND L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VI L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner


SRB ASSOCIATES VI L.P.	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	General Partner


SEVIN ROSEN FUND VII L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VII L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner


SEVIN ROSEN VII AFFILIATES FUND L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VII L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner

SRB ASSOCIATES VII L.P.	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	General Partner

SEVIN ROSEN FUND VIII L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VIII L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner


SEVIN ROSEN VIII AFFILIATES FUND L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VIII L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner

SRB ASSOCIATES VIII L.P.	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	General Partner


JON W. BAYLESS	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact


STEPHEN M. DOW	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact


STEPHEN L. DOMENIK	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact


JOHN V. JAGGERS	/s/ John V. Jaggers
	Signature

CHARLES H. PHIPPS	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact


JACKIE R. KIMZEY	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact

DAVID A. SHRIGLEY	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact

ALAN R. SCHUELE	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact

EXHIBIT INDEX

Exhibit		Found on Sequentially Numbered Page
Exhibit A: Agreement of Joint Filing		26

Exhibit B: Reference to John Jaggers as Attorney-In-Fact		29

EXHIBIT A

Agreement of Joint Filing

The undersigned hereby agree that a single Schedule 13G (or any amendment thereto) relating to the Common Stock of Cytokinetics, Inc. shall be filed on behalf of each of the undersigned and that this Agreement shall be filed as an exhibit to such Schedule 13G.

Dated: February 11, 2005

SEVIN ROSEN FUND VI L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VI L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner


SEVIN ROSEN VI AFFILIATES FUND L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VI L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner


SRB ASSOCIATES VI L.P.	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	General Partner


SEVIN ROSEN FUND VII L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VII L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner


SEVIN ROSEN VII AFFILIATES FUND L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VII L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner

SRB ASSOCIATES VII L.P.	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	General Partner


SEVIN ROSEN FUND VIII L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VIII L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner


SEVIN ROSEN VIII AFFILIATES FUND L.P.	/s/ John V. Jaggers
By SRB ASSOCIATES VIII L.P.,	Signature
Its General Partner
	John V. Jaggers
	General Partner


SRB ASSOCIATES VIII L.P.	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	General Partner


JON W. BAYLESS	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact


STEPHEN M. DOW	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact

STEPHEN L. DOMENIK	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact


JOHN V. JAGGERS	/s/ John V. Jaggers
	Signature

CHARLES H. PHIPPS	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact


JACKIE R. KIMZEY	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact


DAVID A. SHRIGLEY	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact


ALAN R. SCHUELE	/s/ John V. Jaggers
	Signature

	John V. Jaggers
	Attorney-In-Fact

EXHIBIT B

John V. Jaggers has signed the enclosed documents as Attorney-in-Fact. Note that copies of the applicable Powers of Attorney are already on file with the appropriate agencies.