Ishida K, Osakabe M, Eizuka M, et al. - On the basis of the immunohistochemical expression of the markers MUC2, MUC5AC, MUC6, CD10, CDX-2 and cytokeratin 20, the expression of gastrointestinal differentiation markers in resected perihilar (n = 30) and distal (n = 54) cholangiocarcinomas (CCAs) were investigated by researchers in order to assess the role of gastrointestinal differentiation marker expression in extrahepatic CCA based on tumor location. In comparison with subgroup 2, among the perihilar CCAs, subgroup 1 was distinguished by lower expression of MUC5AC and MUC6, a bigger median tumor size, and a significantly worse prognosis. Independent predictors of individual survival were the immunohistological subgroup and the TNM stage. Gastrointestinal differentiation marker profiles were beneficial for stratification of perihilar and distal CCAs, and could play a critical role in tumor development, especially in perihilar CCA.