A Medline search was performed to identify relevant bibliography published between 2013 and 2022 using search combined terms including: “nrf2 coumarin”, “HO-1 coumarin”, “nrf2 IBD”, “nrf2 colitis”, “nfr2 coumarin colitis”, “nrf2 IBD coumarin”, HO IBD”, “HO IBB coumarin”, “HO-1 colitis”, “keap1 coumarin”, and “HO-1 colitis coumarin”. Here, HMOX1 is linked to inflammatory bowel disease.