BCR signaling and its component BTK have direct pathogenic roles in the development of multiple B-cell malignancies, including chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL) and Waldenstrom’s macroglobulinemia (WM) [1]. Here, BCR is linked to mantle cell lymphoma.