CAFs are prolific producers of soluble factors implicated in tumor immunosuppression such as transforming growth factor beta (TGF-β), indoleamine-2,3-dioxygenase (IDO), prostaglandin E2 (PGE2), interleukin-6 (IL-6), tumor necrosis factor a (TNF-α), and VEGF (2). This evidence concerns the gene IL6 and neoplasm.