Introgen Therapeutics (INGNQ) 10-Q 2004 Q2 Quarterly report

EXHIBIT 32.1

CERTIFICATION 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, David G. Nance, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Quarterly Report of Introgen Therapeutics, Inc. on Form 10-Q for the quarterly period ended June 30, 2004 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 Quarterly Report fairly presents in all material respects the financial condition and results of operations of Introgen Therapeutics, Inc.

Date: August 16, 2004	By:	/s/ David G. Nance
	Name:  David G. Nance
	Title:    Chief Executive Officer

I, James W. Albrecht, Jr., certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that the Quarterly Report of Introgen Therapeutics, Inc. on Form 10-Q for the quarterly period ended June 30, 2004 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 Quarterly Report fairly presents in all material respects the financial condition and results of operations of Introgen Therapeutics, Inc.

Date: August 16, 2004	By:	/s/ James W. Albrecht, Jr.
	Name:  James W. Albrecht, Jr.
	Title:    Chief Financial Officer