1. Department of Hematology and Oncology, Mayo Clinic, Scottsdale, AZ, USA;
2. Department of Hematology and Oncology, Oregon Health and Science University, Portland, OR, USA;
3. Department of Internal Medicine, Mayo Clinic, Scottsdale, AZ, USA;
4. Department of Biostatistics, Mayo Clinic, Scottsdale, AZ, USA;
5. Unit of Hematology, Ospedale Papa Giovanni XXIII, Foundation for Research (FROM), Bergamo, Italy;
6. Consorzio Mario Negri Sud, Santa Maria Imbaro (CH), Italy;
7. Istituto Mario Negri Sud, S. Maria Imbaro, Italy;
8. Section of Hematology, University of Florence, Florence, Italy