1. The University of Iowa College of Medicine; Iowa City, Iowa
2. Departments of Radiation Oncology; The University of Iowa College of Medicine; Iowa City, Iowa
3. Department of Pathology and Division of Cellular Molecular Biology and the Ontario Cancer Institute/Princess Margaret Hospital Toronto, and University of Toronto; Ontario, Canada
4. Departments of Surgery; The University of Iowa College of Medicine; Iowa City, Iowa
5. Veterans Affairs Medical Center; Iowa City, Iowa