Patients and ppub of clinical data
All patients had been enrolled in a phase II clinical trial at the National Cancer Center of Korea, as approved by the institutional review board (IRB No. NCCCTC-09-411). Enrolled patients had undergone surgical resection for BTC and were then treated with gemcitabine (1,000 mg/m2) as an adjuvant chemotherapy. The participants voluntarily agreed to donate the materials by signing an informed consent form. Tumor samples were obtained from surgical specimens and blood from seven patients with BTC.