Another mechanism that may also be responsible for altered NK cell function in MM includes upregulation of IRs such as PD-1 on NK cells found in the peripheral blood or BM of MM, which may lead to decreased NK cell function due to its engagement with its ligands PD-L1/2 on MM cells (71, 73, 74) (Figure 3A). Here, CD274 is linked to Miyoshi myopathy.