El Badawy et al. supposed that NRF2 and its downstream enzymes, such as HO-1, has a beneficial role in the gastroprotection against indomethacin-induced gastric ulcer (El Badawy et al. 2021), also other studies showed that HO-1 induction has a beneficial role in NSAIDS-induced gastric damage (Lee et al. 2012), well agreed with our study that showed a significant reduction in NRF2 and HO-1 levels after INDO administration compared to the control group. This evidence concerns the gene NFE2L2 and gastric ulcer.