Since it has been reported by An et al. (19) that PD-L1 expression increases during osteoclastogenesis and mature osteoclasts induce PD-L1 expression on MM cell lines, we performed the analysis of PD-L1/PD-1 distribution by splitting MM patients into osteolytic and not osteolytic, according to the presence or absence of bone disease. This evidence concerns the gene PDCD1 and Miyoshi myopathy.