GPI and gastric cancer: Glucose-6-phosphate isomerase (GPI) catalyzes glucose-6-phosphate (G6P) toward fructose-6-phosphate (F6P), and its overexpression is documented in various cancer types, such as lung adenocarcinoma (Han et al., 2021) and gastric cancer (Ma et al., 2018), associated with highly activated Warburg effect phenotype of cancer cells and poor prognosis.