We have performed a retrospective analysis of a single institution cohort of extrahepatic cholangiocarcinoma patients with expression of TILs and PD-L1 in tumor microenvironment to improve our understanding of their significance and to provide potential rationale for the utility of PD-1 blockade immunotherapy option in cholangiocarcinoma. The gene discussed is PDCD1; the disease is cholangiocarcinoma.