IL9 and colorectal carcinoma: In view of the importance and increasing data about TH9, TH17, and TH22 cells and their associated cytokines in the initiation and development of CRC, here, we review recent findings, with an emphasis on the function of TH9/IL-9, TH17/IL-17, and TH22/IL-22 in the pathogenesis of CRCs, and discuss the therapeutic significance of these main cytokines in the prophylaxis of CRC.