FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
MPM BIOEQUITIES MASTER FUND LP
   2. Issuer Name and Ticker or Trading Symbol
RIGEL PHARMACEUTICALS INC [RIGL] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O MPM ASSET MANAGEMENT, 111 HUNTINGTON AVENUE, 31ST FLOOR		 3. Date of Earliest Transaction (Month/Day/Year)
02/19/2004
(Street)

BOSTON, MA 02199		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 02/19/2004   S   172,373 (1) D $ 20 4,350,516 I See Footnote (2)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
MPM BIOEQUITIES MASTER FUND LP
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVENUE, 31ST FLOOR
BOSTON, MA 02199		     X    
MPM BIOEQUITIES GP LP
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVENUE, 31ST FLOOR
BOSTON, MA 02199		     X    
MPM BIOEQUITIES GP LLC
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVENUE, 31ST FLOOR
BOSTON, MA 02199		     X    
MPM BIOEQUITIES FUND GMBH & CO KG
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVENUE, 31ST FLOOR
BOSTON, MA 02199		     X    
EVNIN LUKE
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVENUE, 31ST FLOOR
BOSTON, MA 02199		     X    
GADICKE ANSBERT
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVENUE, 31ST FLOOR
BOSTON, MA 02199		     X    
LIPTAK ROBERT
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVENUE, 31ST FLOOR
BOSTON, MA 02199		     X    
EMSTER KURT VON
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVENUE, 31ST FLOOR
BOSTON, MA 02199		     X    

Signatures

 By Luke Evnin manager of MPM BioEquities GP LLC, the general partner of MPM BIoEquities GP, LP, the general partner of MPM BioEquities Master Fund, L.P. /s/ Luke Evnin   02/23/2004
**Signature of Reporting Person Date
 By Luke Evnin manager of MPM BioEquities GP LLC, the general partner of MPM BIoEquities GP, LP /s/ Luke Evnin   02/23/2004
**Signature of Reporting Person Date
 By Luke Evnin manager of MPM Bioequities GP LLC /s/ Luke Evnin   02/23/2004
**Signature of Reporting Person Date
 By Luke Evnin manager of MPM BioEquities GP LLC, the general partner of MPM BIoEquities GP, LP, the general partner of MPM BioEquities Fund GmbH & Co. KG /s/ Luke Evnin   02/23/2004
**Signature of Reporting Person Date
 /s/ Luke Evnin   02/23/2004
**Signature of Reporting Person Date
 /s/ Ansbert Gadicke   02/23/2004
**Signature of Reporting Person Date
 /s/ Robert Liptak   02/23/2004
**Signature of Reporting Person Date
 /s/ Kurt von Emster   02/23/2004
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) See Form 4 filed for MPM BioVentures III-QP, L.P. for additional members of this joint filing. The shares were sold as follows: 9,648 by MPM BioVentures III, L.P. ("BVIII"); 143,488 by MPM BioVentures III-QP, L.P. ("BVIII QP"); 12,126 by MPM BioVentures III GmbH & Co. Beteiligungs KG ("BVIII KG"); 4,333 by MPM Bioventures III Parallel Fund, L.P. ("BVIII PF"); and 2,778 by MPM Asset Management Investors 2003 BVIII LLC ("BVAM LLC"). MPM BioVentures III GP, L.P. ("BVIII GP") and MPM BioVentures III LLC ("BVIII LLC") are the direct and indirect partners of BVIII, BVIII QP, BVIII PF and BVIII KG.
(2) The shares are held as follows: 182,511 by MPM BioEquities Master Fund, L.P. ("BEMF") and 100 by MPM BioEquities Fund GmbH & Co. KG ("BEFG"), who are under common control with BVIII; 233,277 by BVIII; 3,469,459 by BVIII QP; 293,213 by BVIII KG; 104,782 by BVIII PF; and 67,174 by BVAM LLC. MPM BioEquities GP, LP ("BE LP") and MPM BioEquities GP, LLC ("BE LLC"), are the direct and indirect general partners of BEMF and BEFG. Luke Evnin ("LE"), Ansbert Gadicke ("AG"), Nicholas Galakatos ("NG"), Dennis Henner ("DH"), Michael Steinmetz ("MS") and Kurt Wheeler ("KW") are the members of BVIII LLC. LE, AG, Robert Liptak and Kurt von Emster are members of BE LLC. LE, AG, NG, DH, Nicholas Simon, III, MS and KW are members of BVAM LLC. Each member of the group disclaims beneficial ownership of the securities except to the extent of its pecuniary interest therein.

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