Malignant plasma cells express high levels of CXCR4 chemokine receptors, which cause cell migration and adhesion to stromal cells secreting the CXCR4 ligand, CXCL12 (SDF-1). NOX A12 is a specific CXCL12 antagonist and may improve chemotherapy by disrupting CXCR4-CXCL12 interactions, thereby mobilizing plasma cells from protective tissue microenvironments to the blood. Furthermore, SDF-1 inhibition may alter the activation status of plasma cells, thereby triggering apoptosis or sensitization of plasma cells towards chemotherapy.