B cell maturation antigen (BCMA) or CD269, also known as tumor necrosis factor receptor superfamily member 17 (TNFRSF-17), is restrictively expressed in both normal and malignant plasma cells (PC) at high levels, which makes it an ideal target antigen for novel MM therapies [16, 17]. Here, TNFRSF17 is linked to Miyoshi myopathy.