1. Molecular Pharmacology Section, Cancer Therapeutics Branch and Clinical Pharmacology Research Core, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, Pharmaceutical Institute, Poppelsdorf, University of Bonn, Bonn, Germany, Center for Cancer Research, Children's Research Institute, and Department of Pediatrics and Biochemistry/Molecular Biology, George Washington University School of Medicine, Washington, DC 22037, Institute of Pharmacy,...