The first experience with immune checkpoint inhibitors (ICIs) in CCA was the Keynote-028 study [118], a phase 1 multicenter study using pembrolizumab in 24 selected patients with programmed death-ligand 1 (PD-L1) positive advanced CCA or gallbladder cancer after failure to respond to standard therapies. The gene discussed is CD274; the disease is cholangiocarcinoma.