1. Adult Bone Marrow Transplant Service, Memorial Sloan Kettering Cancer Center, New York, USA
2. Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy
3. Hematology Service, Hospital Universitario Ramon y Cajal, Madrid, Spain
4. Department of Medicine, Lymphoma Service, Memorial Sloan Kettering Cancer Center, New York, USA