Biliary tract carcinoma is a relatively rare tumor with a poor prognosis. Surgical resection is the only potential cure. However, the efficacy of chemotherapeutic agents is disappointing in advanced or recurrent cases. Gemcitabine (GEM) appears to be one of the most promising chemotherapeutic agents in biliary tract carcinoma, and ribonucleotide reductase subunit M1 (RRM1) plays an important ro...