CXCL8 and cancer: Several SNPs within the IL-8 gene, including T−251A (rs4073), C + 781T (rs2227306), C + 1633T (rs2227543), and A + 2767T (rs1126647), have been widely studied in their associations with different cancers (summarized in [14]); in particular, the A allele of IL-8 rs4073, located in the promoter region of IL-8, is associated with the overexpression of the IL-8 protein [15,16,17].