CXCR4 and cancer: The chemokine CXCL12 (stromal cell-derived factor-1α) binds to the CXCR4 and CXCR7 receptors, initiating divergent signaling pathways that result in chemotaxis, cell survival and/or proliferation, increased intracellular calcium and transcription of genes critical for cell inflammation and cancer metastases [4], [5].