Inhibition of BET protein, the reader of histone acetylation, inhibits IFN-γ-induced PD-L1 expression (59, 60) In addition, in mouse models of ovarian cancer, BET inhibitors can reduce PD-L1 expression in tumor cells, tumor-associated dendritic cells and macrophages, thereby limiting tumor progression (61). This evidence concerns the gene CD274 and ovarian carcinoma.