PTGES and inflammatory bowel disease: However, expression of COX‐2 and mPGES1 is not limited to the sites of acute inflammation but widely seen in tissues of chronic inflammation such as the joints of rheumatoid arthritis (RA) patients, the spinal cord of multiple sclerosis (MS) patients, the colon of inflammatory bowel disease (IBD) patients, the cerebral arterial wall of cerebral aneurysm patients and tumours and their micro‐environment of many cancers (Ricciotti and FitzGerald, 2011; Wang and DuBois, 2018).