I currently serve as Chair and the Henry K. Pancoast Professor of the Department of Radiation Oncology at the University of Pennsylvania. I am an active clinician and board certified in radiation oncology, medical oncology and internal medicine. My research interests include the investigation of the tumor microenvironment in a variety of human tumors including brain tumors, the molecular determinants of the tumor microenvironment, particularly aberrant signal transduction pathways, and the evaluation of proton therapy as a means to improve the therapeutic index of radiation therapy. I have been a faculty member in the Flims Course for Clinical Trials Methodology for eight years and am currently one of the course directors. I have also been a faculty member in the AACR/ASCO-sponsored Vail Course for Clinical Trials Methodology for five years. At the ASTRO Annual Meetings I have served as Vice-chair of the Research Evaluation Committee, Scientific Program Chair and Associate Chair of the Annual Meeting and Program Committee.