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 BIOVENTURES III QP 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 AVE., 31ST FLOOR
3. Date of Earliest Transaction (Month/Day/Year)
05/20/2004
(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 05/20/2004   S   139,313 (1) D $ 17.2479 3,536,258 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 BIOVENTURES III QP LP
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVE., 31ST FLOOR
BOSTON, MA 02199
    X    
MPM BIOVENTURES III LP
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVE., 31ST FLOOR
BOSTON, MA 02199
    X    
MPM BIOVENTURES III GMBH & CO
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVE., 31ST FLOOR
BOSTON, MA 02199
    X    
MPM BIOVENTURES III PARALLEL FUND
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVE., 31ST FLOOR
BOSTON, MA 02199
    X    
MPM ASSET MANAGEMENT INVESTORS 2003 BVIII LLC
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVE., 31ST FLOOR
BOSTON, MA 02199
    X    
MPM BIOVENTURES III GP LP
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVE., 31ST FLOOR
BOSTON, MA 02199
    X    
MPM BIOVENTURES III LLC
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVE., 31ST FLOOR
BOSTON, MA 02199
    X    
GALAKATOS NICHOLAS
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVE., 31ST FLOOR
BOSTON, MA 02199
    X    
STEINMETZ MICHAEL
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVE., 31ST FLOOR
BOSTON, MA 02199
    X    
WHEELER KURT
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVE., 31ST FLOOR
BOSTON, MA 02199
    X    

Signatures

 By Luke Evnin, member of MPM BioVentures III LLC, the general partner of MPM BioVentures III GP, L.P., the general partner of MPM BioVentures III-QP, L.P /s/ Luke Evnin   05/21/2004
**Signature of Reporting Person Date

 By Luke Evnin, member of MPM BioVentures III LLC, the general partner of MPM BioVentures III GP, L.P., the general partner of MPM BioVentures III, L.P /s/ Luke Evnin   05/21/2004
**Signature of Reporting Person Date

 By Luke Evnin, member of MPM BioVentures III LLC, the gp of MPM BioVentures III GP, L.P., the gpof MPM BioVentures III GmbH & Co. Beteiligungs KG /s/ Luke Evnin   05/21/2004
**Signature of Reporting Person Date

 By Luke Evnin, member of MPM BioVentures III LLC, the general partner of MPM BioVentures III GP, L.P., the general partner of MPM BioVentures III Parallel Fund, L.P /s/ Luke Evnin   05/21/2004
**Signature of Reporting Person Date

 By Luke Evnin, manager of MPM Asset Management Investors 2003 BVIII LLC /s/ Luke Evnin   05/21/2004
**Signature of Reporting Person Date

 By Luke Evnin, member of MPM BioVentures III, LLC, the general partner of MPM BioVentures III GP, L.P. /s/ Luke Evnin   05/21/2004
**Signature of Reporting Person Date

 By Luke Evnin, member of MPM BioVentures III, LLC /s/ Luke Evnin   05/21/2004
**Signature of Reporting Person Date

 /s/ Nicholas Galakatos   05/21/2004
**Signature of Reporting Person Date

 /s/ Michael Steinmetz   05/21/2004
**Signature of Reporting Person Date

 /s/ Kurt Wheeler   05/21/2004
**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 Luke Evnin for additional members of this joint filing. The shares were sold as follows: 7,797 by MPM BioVentures III, L.P. ("BVIII"); 115,967 by MPM BioVentures III-QP, L.P. ("BVIII QP"); 9,801 by MPM BioVentures III GmbH & Co. Beteiligungs KG ("BVIII KG"); 3,502 by MPM Bioventures III Parallel Fund, L.P. ("BVIII PF"); and 2,246 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: 197,925 by BVIII; 2,943,662 by BVIII QP; 248,776 by BVIII KG; 88,902 by BVIII PF; and 56,993 by BVAM LLC. Luke Evnin, Ansbert Gadicke, Nicholas Galakatos, Dennis Henner, Nicholas Simon, III, Michael Steinmetz and Kurt Wheeler are the members of BVIII LLC and 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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