AQP4 and chronic atrophic gastritis: The study indicated that the expression of these AQPs in the stomach increases during ethanol-induced edema and after gastric injury.99 In a separate study, it was demonstrated that AQP3, along with other AQP5, AQP7, and AQP11, exhibited upregulation at the mRNA level in cases of atrophic gastritis.100 Thus, these findings suggest that the expression of various AQP subtypes (including AQP1, AQP3, AQP4, AQP5, AQP7, and AQP11) is heightened in the presence of gastritis.