Activation of Stat3 with IL-6, IL-21 and IL-23, the production of which is up-regulated in CRC tissue [39,40,41], was accompanied by enhanced hepcidin induction in colonic epithelial cells, and the knockdown of Stat3 with a specific antisense oligonucleotide abrogated the cytokine-driven hepcidin synthesis. This evidence concerns the gene IL21 and colorectal carcinoma.