1. Department of Medicine, University Hospitals Case Medical Center, Cleveland, OH, USA;
2. Myeloma Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, USA;
3. Department of Lymphoma and Myeloma, University of Texas MD Anderson Cancer Center, Houston, TX, USA;
4. Lymphoid Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA;
5. Biostatistics and Data Management Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA;
6. Hematology Section, Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA