Approved immunotherapies for MM target key surface antigens include B-cell maturation antigen (BCMA, gene ID: TNFRSF17), cluster of differentiation 38 (CD38), signaling lymphocytic activation molecule family member 7 (SLAMF7), and G protein-coupled receptor class C group 5 member D (GPRC5D). The gene discussed is GPRC5D; the disease is Miyoshi myopathy.