1. Flow Cytometry Unit, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
2. Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD
3. Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
4. Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
5. Biostatistics and Data Management Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD