Kriegsmann et al. showed that PD-L1 expression in BTC cells was comparable between ICC (5%), PHC (4%), and DCC (3%), whereas PD-L1 expression in stromal cells was the highest in DCC (61% in DCC, 40% in PHC, and 31% in ICC) [40]. The gene discussed is CD274; the disease is intrahepatic cholangiocarcinoma.