IL4 and colon adenocarcinoma: As for the key gene RORC, the mechanism leading to a low risk of COAD may be that the over-expression of the target gene RORC, which is located the downstream of IL-4/IL-13 pathway, can cause primitive CD4+ T cells to polarize into the Th17 cells, then the Th17 cell secretes IL-17 and IFNγ (Fig. 16).