1. J. N. Weinstein, T. G. Myers, P. M. O'Connor, A. J. Fornace Jr., K. W. Kohn, J. K. Buolamwini, W. W. van Osdol, and V. N. Viswanadhan are at the Laboratory of Molecular Pharmacology (LMP), Division of Basic Science, National Cancer Institute (NCI), National Institutes of Health (NIH), Building 37, Room 5C-25, 9000 Rockville Pike, Bethesda, MD 20892, USA.
2. S. H. Friend is at the Fred Hutchinson Cancer Research Center-NCI, Seattle, WA 98105, USA.
3. T. Fojo and S. E. Bates are in the Medicine Branch, Division of Clinical Science, NCI, NIH, Bethesda, MD 20892, USA.
4. L. V. Rubinstein is in the Biometric Research Branch, Cancer Therapy Evaluation Program, Division of Cancer Treatment, Diagnosis, and Centers (DCTDC), NCI, NIH, Bethesda, MD 20892, USA.
5. N. L. Anderson is with Large Scale Biology, Rockville, MD 20850, USA.
6. A. P. Monks and D. A. Scudiero are at the SAIC-NCI-Frederick Cancer Research and Development Center (FCRDC), Frederick, MD 21701, USA.
7. E. A. Sausville is in the Developmental Therapeutics Program (DTP), DCTDC, NCI, NIH, Bethesda, MD 20892, USA.
8. D. W. Zaharevitz and K. D. Paull are in the Information Technology Branch, DTP, DCTDC, NCI, NIH, Bethesda, MD 20892, USA.
9. G. S. Johnson is in the Grants and Contracts Operations Branch, DTP, DCTDC, NCI, NIH, Bethesda, MD 20892, USA.
10. R. E. Wittes is in the Office of the Director, DCTDC, NCI, NIH, Bethesda, MD 20892, USA.