CXCR1 and neoplasm: These chemokines interact with the promiscuous chemokine receptor, CXCR2, expressed on neutrophils, as well as on many types of tumor cells, to initiate the influx of pro-tumoral neutrophils of the MDSC phenotype, while IL-8 interacts selectively with CXCR1 [12,13,15,16,17,19,22,23].