1. Department of Oncology (G.E.S., A.W., H.-J.L., R.R.,M.B.M., A.S.), Lombardi Cancer Center, Georgetown University, Washington, DC 20007
2. Department of Pharmacology (T.F.F.), Columbia University, New York, New York 10032
3. Department of Pharmacology and Toxicology (F.C.), Philipps University, School of Medicine, 35033 Marburg, Germany
4. School of Nursing and Health Studies (E.M., A.S.), Georgetown University, Washington, DC 20007