TNFRSF17 and Miyoshi myopathy: Another potential disadvantage for BCMA as a CAR-T target lies in that BCMA can be actively shed from the MM cell surface by γ-secretase complex, which in turn lowers surface BCMA expression on MM cells for CAR-T cell recognition and also releases the soluble form of BCMA, which can diminish CAR T cell effector function10.