Methods: We analyzed syndecan-1 expression in a large, clinicopathologically well-characterized collective of 154 intrahepatic cholangiocarcinoma, 221 extrahepatic cholangiocarcinomas, and 95 gallbladder carcinomas as well as respective normal tissues and precursor lesions by immunohistochemistry with digital image analysis and correlated with recurrence-free survival and prognostic markers. The gene discussed is SDC1; the disease is intrahepatic cholangiocarcinoma.