CXCR4 and breast carcinoma: In pre-clinical models, it has been demonstrated that ANGPTL2 strengthens responsiveness of breast cancer cells to chemokine (C-X-C motif) ligand 12 (CXCL12) by the up-regulation of chemokine (C-X-C motif) chemokine receptor 4 (CXCR4) in those cells [11].