MUC1 and ampulla of vater adenocarcinoma: Survival in patient with tumors of pancreatobiliary type or CK7/MUC1‐positive or CDX2‐negative ampullary tumors seem to have a worse prognosis which is similar to that of patients with pancreatic cancer.6, 7, 8 In a Korean study of 37 patients with ampullary adenocarcinoma who underwent Whipple procedure, half of them (18/37) had CK7‐positive tumors.