1. Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD;
2. Section of Hematology and Medical Oncology, Department of Medicine, Tulane University, New Orleans, LA;
3. Office of Biostatistics Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD;
4. Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY;
5. Lymphoid Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD;
6. Institut d'Investigacions Biomediques August Pi i Sunyer, Barcelona, Spain; and
7. Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD