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 *
SIMON NICHOLAS J III
   2. Issuer Name and Ticker or Trading Symbol
RIGEL PHARMACEUTICALS INC [RIGL] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ 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)
08/31/2004
(Street)

BOSTON, MA 02199		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ 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 08/31/2004   S   60,527 (1) D $ 20.5962 1,711,572 I See Footnote (2)
Common Stock 09/01/2004   S   24,500 (3) D $ 21.1314 1,687,072 I See Footnote (4)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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
SIMON NICHOLAS J III
C/O MPM ASSET MANAGEMENT
111 HUNTINGTON AVENUE, 31ST FLOOR
BOSTON, MA 02199		   X   X    

Signatures

 /s/ Nicholas J. Simon, III   09/02/2004
**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) The shares were sold as follows: 3,388 by MPM BioVentures III, L.P. ("BVIII"); 50,384 by MPM BioVentures III-QP, L.P. ("BVIII QP"); 4,258 by MPM BioVentures III GmbH & Co. Beteiligungs KG ("BVIII KG"); 1,522 by MPM BioVentures III Parallel Fund, L.P. ("BVIII PF"); and 975 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: 95,793 by BVIII; 1,424,746 by BVIII QP; 120,409 by BVIII KG; 43,029 by BVIII PF; and 27,595 by BVAM LLC. The Reporting Person is a member of BVIII LLC and BVAM LLC. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein.
(3) The shares were sold as follows: 1,371 by BVIII; 20,394 by BVIII QP; 1,724 by BVIII KG; 616 by BVIII PF; and 395 BVAM LLC. BVIII GP and BVIII LLC are the direct and indirect partners of BVIII, BVIII QP, BVIII PF and BVIII KG.
(4) The shares are held as follows: 94,422 BVIII; 1,404,352 by BVIII QP; 118,685 by BVIII KG; 42,413 by BVIII PF; and 27,200 by BVAM LLC. The Reporting Person is a member of BVIII LLC and BVAM LLC. The Reporting Person disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein.

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