Genentech 10-K 2007 FY Annual report

EXHIBIT 32.1

CERTIFICATIONS OF

CHIEF EXECUTIVE OFFICER AND CHIEF FINANCIAL OFFICER

PURSUANT TO 18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Arthur D. Levinson, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Annual Report of Genentech, Inc. on Form 10-K for the year ended December 31, 2007 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that information contained in such Annual Report of Genentech, Inc. on Form 10-K fairly presents in all material respects the financial condition and results of operations of Genentech, Inc.

By:	/s/ ARTHUR D. LEVINSON
Name: Title:	Arthur D. Levinson, Ph.D. Chief Executive Officer
Date:	February 25, 2008

I, David A. Ebersman, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Annual Report of Genentech, Inc. on Form 10-K for the year ended December 31, 2007 fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 and that information contained in such Annual Report of Genentech, Inc. on Form 10-K fairly presents in all material respects the financial condition and results of operations of Genentech, Inc.

By:	/s/ DAVID A. EBERSMAN
Name: Title:	David A. Ebersman Executive Vice President and    Chief Financial Officer
Date:	February 25, 2008