1. Pfizer Global Research and Development, Cambridge Laboratories, Pfizer, Inc., Cambridge, Massachusetts 02139, United States
2. Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
3. Department of Oncology, Georgetown University, 3700 O Street NW, Washington, DC 20057, United States
4. Department of Biochemistry and Molecular & Cellular Oncology, Georgetown University, 3700 O Street NW, Washington, DC 20057, United States
5. Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, United States