PDCD1 and neoplasm: PD-L1 is 50% expressed in Epstein-Barr virus (EBV)+ GC tumor cells and 94% in immune cells, while in EBV− GC the PD-L1 expression was positive only when associated with microsatellite instability (MSI), suggesting that patients with EBV+ and MSI GC may have better response to PD-1 blocking therapy [85].