Finally, various orally active small-molecule non-competitive antagonists of CXCR1 and CXCR2, such as SCH527123 (Merck) [322], repertaxin (Dompé, Milan, Italy), and SCH479833 (Merck, Whitehouse Station, NJ, USA), have demonstrated anti-tumor effects in breast cancer xenograft models [323]. Here, CXCR2 is linked to breast cancer.