KRAS and duodenal adenocarcinoma: In particular, Matsubara et al. described GNAS and KRAS gene mutations in 28% and 2% of gastric heterotopias, and in 17% and 37% of duodenal adenocarcinomas, respectively, supporting a pathogenetic link between gastric heterotopias and gastric-type adenomas or duodenal adenocarcinomas [35].