Programmed death ligand 1 expression in human intrahepatic cholangiocarcinoma and its association with prognosis and CD8 + T-cell immune responses

Background Agents targeting the programmed death ligand 1 (PD-L1)/programmed death receptor 1 immune checkpoint exhibited promising clinical outcomes in a variety of malignant tumors, including intrahepatic cholangiocarcinoma (ICC). However, the relationship between PD-L1 expression and CD8+ T-cell immune responses is not well defined in ICC.