In MM patients, monoclonal antibodies (mAbs) targeting CD38 (e.g., daratumumab), bi-specific mAbs or chimeric antigen receptor T (CAR-T) cells against the B cell maturation antigen (BCMA) or G protein–coupled receptor, class C, group 5, member D (GPRC5D) have been proven beneficial, particularly in advanced disease stages (Table 2) (3, 4, 224). Here, CD38 is linked to Miyoshi myopathy.