PDCD1 and Miyoshi myopathy: Although blockade of PD-1 with nivolumab did not noticeably affect MM cell viability or enhance daratumumab-mediated MM cell killing in these short-term ex vivo experiments (Figure 3A), nivolumab treatment resulted in a mild but clear increase in T-cell frequency (1.15 fold increase compared to control antibody; p = 0.003; Figure 3B), which is predominantly driven by an increase in CD8+ T-cells (1.59 fold increase; p = 0.001), while the CD4+ T-cells remain unchanged (1.03 fold increase; p = 0.43).