PSMB5 and Miyoshi myopathy: With respect to PSMB5 mutation, Ri et al.11 found that the degree of drug resistance in transfected cell line PSMB5-tKMS-11 was lower than that in BTZ-induced KMS-11/BTZ-resistant cell lines, and the mutation was not found in some drug-resistant MM cell lines12 and drug-resistant MM patients13.