Using the CRBN65 antibody, we found that MM patients with CRBN(+) have a superior response rate to thalidomide- or lenalidomide-based therapy compared to those with CRBN(-) (ORR ≥PR vs. SD/PD, p = 0.012; ORR ≥ VGPR vs. PR/PD/SD, p = 0.032). This evidence concerns the gene CRBN and Miyoshi myopathy.