1. National Cancer Institute, National Institute of Arthritis and Metabolic Diseases, and Clinical Center, National Institutes of Health, Bethesda, Md.
2. National Cancer Institute, National Institutes of Health, Bethesda, Md.
3. Section of Hematology, Laboratory of Experimental Pathology, National Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda, Md.
4. Section on Hematology, Clinical Pathology Department, Clinical Center, National institutes of Health, Bethesda, Md.
5. Section of Hematology, Laboratory of Experimental Pathology, National Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda, Md.; at present: Director of Research, St. Elizabeth's Hospital, Boston, Mass.