CXCR1 and neoplasm: CXCR1 and CXCR2 receptors are expressed on the surface of neutrophils [16], and tumor cells can secret cytokines such as CXCL1, CXCL2, and IL-8 through autocrine and paracrine, and these cytokines can bind to the corresponding receptors on the surface of neutrophils [74].