It has been also reported that the cleavage of B cell maturation antigen (BCMA) on the surface of multiple myeloma (MM) cells and the subsequent release of soluble BCMA (sBCMA) caused by the multi-subunit γ-secretase complex (GS) is an important mechanism for reducing CAR-T efficacy. This evidence concerns the gene TNFRSF17 and plasma cell myeloma.