Abbreviations: AA: arachidonic acid; ATG16L1: autophagy related 16 like 1; CD: Crohn disease; CXCL1: C-X-C motif chemokine ligand 1; ER: endoplasmic reticulum; GFP: green fluorescent protein; GPX4: glutathione peroxidase 4; IBD: inflammatory bowel disease; IECs: intestinal epithelial cells; PTGS2/COX2: prostaglandin-endoperoxide synthase 2; PUFA: polyunsaturated fatty acid; SDA: stearidonic acid; TLR2: toll-like receptor 2; WT: wild-type. The gene discussed is PTGS2; the disease is Crohn disease.