CD274 and neoplasm: g. IRF1) are upregulated.53 In this study, we used IFN-γ to simulate the tumor microenvironment, and the results showed that FEN1 downregulation effectively inhibited the expression of PD-L1 that had been induced by IFN-γ, indicating that FEN1 downregulation may regulate the expression of PD-L1 through the JAK/STAT signaling pathway and IFN-γ induction (such as IRF1) (Fig. 7).