CXCR7, a chemokine receptor that may function as a non-signaling scavenger for CXCL12, is expressed in active MM, and inhibition of both CXCR4 and CXCR7 with plerixafor and NOX-A12 functionally interfered with MM cell chemotaxis to the BM, and re-sensitized these cells to proteasome inhibitors (145). This evidence concerns the gene ACKR3 and Miyoshi myopathy.