IL-17 is a pro-inflammatory cytokine, which is associated with many cancer progressions, which is mostly derived of T-helper17 (TH17) cells (20, 21) In colon cancer, published document showed that TH17 was involved in colitis and colitis-related cancer and also could mediate the activity of CTLs in colon cancer development (3, 22). The gene discussed is IL17A; the disease is cancer.