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Certification
Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
(Subsections (a) and (b) of Section 1350, Chapter 63 of Title 18, United States Code)
Pursuant to section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of section 1350, chapter 63 of title 18, United States Code), each of the undersigned officers of ImmunoGen, Inc., a Massachusetts corporation (the "Company"), does hereby certify, to such officer's knowledge, that:
The Annual Report for the year ended June 30, 2004 (the "Form 10-K") of the Company fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and the information contained in the Form 10-K fairly presents, in all material respects, the financial condition and results of operations of the Company.
Dated: August 20, 2004 | /s/ MITCHEL SAYARE Mitchel Sayare Chairman of the Board of Directors, Chief Executive Officer and President | |
Dated: August 20, 2004 | /s/ VIRGINIA A. LAVERY Virginia A. Lavery Vice President, Finance and Treasurer |