CXCR4 and Miyoshi myopathy: The study comprehensively determined the mRNA expression of nine genes that may affect resistance in 73 MM patients treated with bortezomib-based regimens and 11 healthy volunteers: ABCB1, CXCR4, MAF, MARCKS, POMP, PSMB5, RPL5, TXN, and XBP1. The genes were selected on the basis of previous laboratory and clinical studies investigating the bortezomib resistance in MM patients [17,18,19,20,21,25].