CD40 and synovial sarcoma: These data are consistent with prior findings that autoreactive B cell hyperactivity and autoantibody production in autoimmune diseases involves B cell intrinsic innate TLR signals and adaptive T helper cell signals (via CD40) as well as homeostatic regulation by BAFF (23, 67–69) and that depletion of B cells is beneficial for patients with several autoimmune diseases including SLE, RA, SS and MS (70).