CXCR2 and neoplasm: Chemokine receptors CXCR1/CXCR2 and their ligands (CXCL1-3, 5, 8) have been associated with tumor associated neutrophil (TAN) and/or polymorphonuclear–MDSC (PMN-MDSC) infiltration in various tumors [16], including BCa [17], and targeted in patients with breast cancer and prostate cancer [16].