SDC1 and Miyoshi myopathy: To tackle antigen downregulation, CAR-T cell targeting other MM-associated epitopes (i.e. CD138, CD38, CD19, GPRC5D, SLAMF7/CS1, APRIL, TACI, CD229, CD56, MUC1, NKG2D ligands, integrin β7, Kappa light chain, FcRH5, CCR10 and CD44v6) rather than BCMA alone have exhibited encouraging results (113).