In recent studies, aquaporin 5 (AQP5), Trop2 and DDIT4 were shown to reflect parietal cell loss and the severity of SPEM development and could also predict a higher risk of GC (Riera et al., 2020; Lee et al., 2021; Miao et al., 2021). The gene discussed is AQP5; the disease is gastric cancer.