Lecture : Gemcitabine plus cisplatin (GemCis) has been the standard chemotherapy for unresectable or metastatic biliary tract cancer including gallbladder cancer, since the positive results of the randomized phase 3 ABC-02 study. In this study, GemCis has demonstrated median progression-free survival (PFS) and overall survival (OS) of 8.0 months and 11.7 months, respectively. In terms of response rates, gallbladder cancer showed higher response rates compared to cholangiocarcinoma (37.7% vs 19.0%). 5-FU-based chemotherapy is ‘in facto‘ standard second-line therapy, but survival outcomes were moderate with median PFS and OS of around 2 and 6 months, respectively. Molecular profiling of gallbladder cancer has shown that HER2 overexpression (prevalence 4-10%) might be promising target for future study, as this was effective strategy in HER2-positive breast cancer and gastric cancer patients. In addition, based on the promising phase 2 study results of triplet therapy including nab-paclitaxel or immune checkpoint inhibitors with the backbone of GemCis, multiple phase 3 trials are ongoing for patients with unresectable or metastatic biliary tract cancer. For resected biliary tract cancer patients, adjuvant capecitabine for 6 months has been regarded as a standard therapy based on the BILCAP trial, multicenter randomized phase 3 UK-based trial. German/Dutch ACTICCA-1 phase 3 trial is ongoing to investigate and compare the efficacy and safety of adjuvant capecitabine vs GemCis which is standard therapy for unresectable disease. As far, there is no standard neoadjuvant therapy in gallbladder cancer. However, with recent advances of systemic therapy in palliative setting with higher response rates, neoadjuvant therapy might be the reasonable strategy for locally advanced as well as resectable disease.