The chemokines CXCL1, CXCL2, CXCL5, CXCL6, and CXCL8 secreted from tumor cells attract neutrophils in the blood to the tumor microenvironment via CXCR1 and CXCR2 on the surface of neutrophils [55]. This evidence concerns the gene CXCR2 and neoplasm.