CD200 and Miyoshi myopathy: In our study, most PC subsets overexpressed CD200 (related to a poor PFS in PC1) and CD28 (related to a worse OS in PC3) in both premalignant MGUS/SMM and active MM, while fewer PC subsets showed an increase in CD117 (both premalignant and active MM stages) and CD56 (active MM) expression.