CXCL8 and neoplasm: CAFs can secret multiple cytokines, chemokines, including interleukin (IL)-6, IL-8, IL-10, IL-4, tumor necrosis factor (TNF), TGF-β, C-X-C motif chemokine ligand (CXCL)9, CXCL10, C-C motif chemokine ligand (CCL)5, CCL2, etc., that may directly or indirectly contribute to tumor progression (64).