PROSPECTUS SUPPLEMENT  FILED PURSUANT TO RULE 424(B)(4) 
   
TO PROSPECTUS DATED MARCH 28, 2001  REGISTRATION NO. 333-37072 

GENENTECH, INC.

SHARES OF COMMON STOCK

     This prospectus supplement relates to the sale by certain selling shareholders of our common stock, par value $.02 per share, that was originally delivered in exchange for Liquid Yield Option Notes due 2015 issued by Roche Holdings, Inc.

     This prospectus supplement should be read in conjunction with the prospectus dated March 28, 2001, which is to be delivered with this prospectus supplement. All capitalized terms used but not defined in the prospectus supplement shall have the meanings given them in the prospectus.

     The table below sets forth information as of the date hereof concerning beneficial ownership of the common stock of the selling shareholders as listed below. All information concerning beneficial ownership has been furnished by the selling shareholders.

NAME  NUMBER OF SHARES OF
COMMON STOCK
OWNED PRIOR TO
OFFERING
NUMBER OF
SHARES OFFERED
NUMBER OF SHARES OF
COMMON STOCK
OWNED AFTER THE
OFFERING
PERCENTAGE OF
COMMON STOCK
OUTSTANDING





UBS AG London Branch 346  346                               0  * 
         
Lydian Overseas
Partners Master Fund L.P.
260,078  260,078                               0  * 
         
Gabriella Vailati  108  108                               0  * 
         
Leonarda Vailati  108  108                               0  * 
         
Giovanni Vailati  108  108                               0  * 
         
Marco Vailati  108  108                               0  * 
 

* Less than 1%         


THE SECURITIES OFFERED HEREBY INVOLVE A HIGH DEGREE OF RISK. SEE
“RISK FACTORS” BEGINNING ON PAGE 3 OF THE PROSPECTUS.

     THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE
SECURITIES AND EXCHANGE COMMISSION NOR HAS THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED





UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY
REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.


The date of this Prospectus Supplement is July 21, 2005.