1. Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY;
2. Lymphoid Malignancy Unit, Division of Molecular Oncology, IRCCS San Raffaele Scientific Institute, Milan, Italy;
3. B cell Neoplasia Unit, Division of Molecular Oncology, IRCCS San Raffaele Scientific Institute, Università Vita-Salute San Raffaele, Milan, Italy;
4. Clinical Unit of Lymphoid Malignancies, Department of Onco-Hematology, IRCCS San Raffaele Scientific Institute, Milan, Italy; and
5. Department of Pathology and Cell Biology and
6. Department of Microbiology and Immunology, Columbia University, New York, NY