1. Clinical Center and National Cancer Institute, National Institutes of Health, Bethesda, Md.
2. Clinical Pathology Department, Clinical Center, National Institutes of Health, Bethesda, Md.
3. Section on Hematology, Clinical Pathology Department, Clinical Center, National Institutes of Health, Bethesda, Md.
4. Clinical Associate, Medicine Branch, National Cancer Institute, National Institutes of Health, Bethesda, Md.