CXCR4 and cancer: Therefore, our functionally circumscribed CXCR4 inhibitor, which blocks chemotaxis and homing of the CXCR4-positive cells to distant organ sites when enriched with CXCL12 in the stroma without disturbing the retention of hematopoietic progenitor cells in the bone marrow, presages a unique therapeutic application of MSX-122 for cancer metastasis or inflammation.