T cell exhaustion is induced by inadequate IFN-gamma and upregulation of inhibitory receptors on T cells, such as programmed cell death protein1 (PD-1), cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), Tim-3, and lymphocyte activation gene-3 (LAG-3), in MM patients [24,26]. Here, CTLA4 is linked to Miyoshi myopathy.