CD274 and neoplasm: The PD1/PD‐L1 blocker is mainly used to block the inhibition of T cells by tumor cells, thereby activating the immune system to attack tumor cells.37 However, in tumors with no or low levels of PD‐L1 expression, the blocker has no inhibitory site and therefore cannot exert antitumor effects.38 When s PD‐1/PD‐L1 blocker is combined with s virus, the OV infects the tumor cells and induces a large number of immune cells (T cells) to infiltrate the tumor.