Deletions and inactivating mutations of the TRAF3 gene have been documented in almost all malignancies of mature B cells, including multiple myeloma (MM), diffuse large B-cell lymphoma (DLBCL), B-cell chronic lymphocytic leukemia (B-CLL), gastric and splenic marginal zone lymphoma (MZL), Hodgkin lymphoma (HL) and Waldenstrom’s macroglobulinemia (WM) (13, 14). Here, TRAF3 is linked to B-cell chronic lymphocytic leukemia.