1. Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA;
2. Alliance Statistics and Data Center, Mayo Clinic, Scottsdale, AZ, USA;
3. Division of Hematology, The Ohio State University Comprehensive Cancer Center, Columbus, OH, USA;
4. Department of Hematologic Malignancies, Dana-Farber/Partners Cancer Care, Boston, MA, USA;
5. Department of Medicine, Stanford School of Medicine, Palo Alto, CA, USA;
6. Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA