Considering the central role that immunotherapy is gaining in MM, other immune checkpoint molecules besides PD-1/PD-L1, especially “lymphocyte activation gene-3” (LAG-3), “T-cell immunoglobulin and mucin containing protein 3” (TIM-3) and “V-domain Ig suppressor of T cell activation” (VISTA) represent a new interesting field of study. Here, LAG3 is linked to Miyoshi myopathy.