PDCD1 and biliary tract cancer: Similarly, in advanced biliary tract cancer patients, chemotherapy (gemcitabine-based, paclitaxel-albumin-based, oxaliplatin + tegafur, or other regiments) plus PD-1 blockade (pembrolizumab or nivolumab) resulted in an overall survival (OS) of 14.9 months compared to 4.1 and 6.0 months, respectively for PD-1 blockade alone and chemotherapy alone [32].