The BCR signaling pathway plays a central role in the onset and progression of mature B cell malignancies, such as chronic lymphocytic leukemia (CLL), mantle-cell lymphoma (MCL), diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), or Waldenström’s macroglobulinemia (WM). The gene discussed is BCR; the disease is diffuse large B-cell lymphoma.