EXHIBIT 99.1 March 20, 2002 Office of the Chief Accountant Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 RE: ARTHUR ANDERSEN LLP REPRESENTATIONS Dear Madam or Sir: In connection with Arthur Andersen LLP's audit of the financial statements of Introgen Therapeutics, Inc. (the "Company") for the six-month transition period ended December 31, 2001, Arthur Andersen LLP has made the following representations to the Company: 1. The audit was subject to Arthur Andersen LLP's quality control system for the U.S. accounting and auditing practice to provide reasonable assurance that the engagement was conducted in compliance with professional standards; 2. There was appropriate continuity of Arthur Andersen LLP personnel working on the audit; 3. Consultation with the national office of Arthur Andersen LLP regarding the audit was available; and 4. Personnel at foreign affiliates of Arthur Andersen LLP were available to conduct the relevant portions of the audit, where applicable. Please contact me if you have any questions regarding the foregoing. Very truly yours, /s/ James W. Albrecht, Jr. James W. Albrecht, Jr. Chief Financial Officer Copy to: David Winn, Arthur Andersen LLP