NOS2 and Abnormal intestine morphology: reported that lansoprazole protected against indomethacin-induced small intestinal injuries in rats by inhibition of iNOS expression and up-regulation of heme oxygenase-1producton (Yoda et al., 2010), and revaprazan, a potassium-competitive acid blocker prevented NSAID enteropathy in rats through enhancing tight junction related mechanisms (Han et al., 2020), which presented a complicated influence of PPIs in NSAID enteropathy.