PDCD1 and Miyoshi myopathy: An increased proportion of PD-1+ T-cells was found in BM samples obtained from NDMM (median 14.1%, p = 0.009), daratumumab-naïve RRMM (median 17.9%, p < 0.001), and daratumumab-refractory MM patients (median 19.0%, p < 0.001), when compared to healthy controls (median 7.1%).