1. Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD;
2. Hematology Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD;
3. Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD;
4. Experimental Transplantation and Immunology, National Cancer Institute, National Institutes of Health, Bethesda, MD;
5. Immunology Section, Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD; and
6. Hematology Section, Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD