CXCR2 and breast carcinoma: We have previously shown that the ligands of human chemokine receptor CXCR2 (CXCL1, CXCl2, CXCL3, CXCL5, CXCL6, CXCL7 and CXCL8) were coregulated in breast cancers, presumably because of their common location in a narrow region of chromosome 4q [12,13].