Biliary Vater carcinoma, originating from the duodenal mucosa and also known as Vater curvular carcinoma, is a rare subtype of biliary tract cancers [46], Intriguingly, in rare biliary Vater carcinomas, heightened AGR2 expression correlates with increased cancer cell proliferation and invasion capabilities [47]. The gene discussed is AGR2; the disease is biliary tract neoplasm.