Despite the encouraging results in MM pre-clinical models showing the efficacy of PD-1 blockade (5–8), early clinical studies on PD-1/PD-L1 inhibitors showed a minimal clinically meaningful anti-MM activity as single agents (9, 10), with only one complete response out of 27 MM patients and stable disease in 63% of the patient cohort treated with nivolumab (9). This evidence concerns the gene PDCD1 and Miyoshi myopathy.