IL-17 is overexpressed in stenosis in CD fibrosis, and IL-17A promotes fibroblast proliferation and survival through metabolic reprogramming (26), and induces epithelial-mesenchymal transition (EMT) in IECs, resulting in raised expression of vimentin, snail and α-SMA and lessened E-cadherin expression (27). The gene discussed is IL17A; the disease is Cowden disease.