CXCR4 and neoplasm: It has been demonstrated that SDF-1/CXCR4 signaling, one of the most important chemokine receptor–ligand complexes, was considered to play multiple roles in cell migration, proliferation, chemotactic responses, adhesion, secretion of MMPs and angiopoietic factors in the development of many systems and tumor cells through some possible pathways [22-26].