CD38 and Miyoshi myopathy: Natural killer (NK) cells are an intriguing immune cell type in MM given the recent development of monoclonal antibodies (mAbs), elotuzumab (anti-SLAMF7), and daratumumab (anti-CD38) that enhance NK cell-mediated tumour cell toxicity by activating the antibody dependent cellular cytotoxicity (ADCC) mechanism (13–15).