BRD4 and viral infectious disease: Interestingly, some BET/BRD4 inhibitors do not affect PRV or PRRSV viral gene transcription (19), and, other previous studies have demonstrated that BRD4 facilitates viral infection through the regulation of HSV-1 and HSV-2 viral gene transcription and that, through inhibiting BRD4, HSV-1 and HSV-2 viral infection, gene transcription, and protein synthesis were significantly suppressed in a dose-dependent manner (21).