CD274 and Epstein-Barr virus infection: Previous clinical trials (8, 9, 24) demonstrated that the PD-L1 CPS score was a useful marker to predict therapeutic response in ICB monotherapy in many cancer types, and MSI-H/dMMR and EBV infection was correlated with more tumor-infiltrating lymphocytes (TILs) and a higher PD-L1 expression in gastric cancer patients, which indicated that these patients might benefit from immunotherapy (25), but the ratio of MSI-H/dMMR to EBV-positive gastric cancer patients was low (26).