Joint Filer Information

Names:
Deerfield Capital L.P., Deerfield Special Situations Fund, L.P., Deerfield Management Company, L.P., Deerfield Special Situations Fund International Limited, Deerfield Partners, L.P., Deerfield International Limited
 
Address:
Deerfield Capital, L.P., Deerfield Special Situations Fund, L.P., Deerfield Partners L.P. and Deerfield Management Company, L.P.:
780 Third Avenue, 37th Floor
New York, NY 10017
 
Deerfield Special Situations Fund International Limited and Deerfield International Limited:
c/o Citi Hedge Fund Services (B.V.I.) Ltd.
Bison Court, P.O. Box 3460
Road Town, Tortola, D8,
British Virgin Islands
 
Designated Filer:
James E. Flynn
 
Issuer and Ticker Symbol:
Rigel Pharmaceuticals, Inc. (RIGL)
 
Date of Event Requiring Statement:
November 3, 2010
 
The undersigned, Deerfield Capital, L.P., Deerfield Special Situations Fund, L.P., Deerfield Management Company, L.P., Deerfield Partners, L.P., Deerfield International Limited and Deerfield Special Situations Fund International Limited are jointly filing the attached Statement of Changes in Beneficial Ownership on Form 4 with James E. Flynn with respect to the beneficial ownership of securities of Rigel Pharmaceuticals, Inc.
 
Signatures:
 
 
DEERFIELD CAPITAL, L.P.
     
By:
J.E. Flynn Capital LLC, General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact
  
 
 
DEERFIELD SPECIAL SITUATIONS FUND, L.P.
     
By:
Deerfield Capital, L.P., General Partner
  
     
By:
J.E. Flynn Capital LLC, General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-in-Fact
 
 
DEERFIELD PARTNERS, L.P.
     
By:
Deerfield Capital, L.P., General Partner
  
     
By:
J.E. Flynn Capital LLC, General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-in-Fact
  
 
 
DEERFIELD MANAGEMENT COMPANY, L.P.
     
By:
Flynn Management LLC, General Partner
  
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-in-Fact
  
 
 
DEERFIELD SPECIAL SITUATIONS FUND INTERNATIONAL LIMITED
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-in-Fact
 
 
DEERFIELD INTERNATIONAL LIMITED
     
By:
/s/ Darren Levine
  
 
Darren Levine, Attorney-In-Fact