CXCR1 and cancer: Elevated expression of IL-8 or CXCR1/CXCR2 has already been featured in cancer cells, tumor-associated macrophages (TAM), and tumor-infiltrating neutrophils (TIN) [19], which suggests that the interaction between IL-8 and CXCR1/CXCR2 may function as a significant regulator under the tumor microenvironment.