CXCL12 and cancer: Among them, CXC Cytokine Ligand 12 (CXCL12, formerly known as stromal cell-derived factor-1, SDF1) and CXC receptor 4 (CXCR4) comprise the CXCL12-CXCR4 axis, which is widely acknowledged as playing a vital role in cancer metastasis.