To determine the specific function of BRD4 in mediating the protective effects against cholestatic injury, hepatic BRD4 was specifically downregulated in Brd4-floxed mice by AAV-TGB-Cre infection for 2 months, FXR was then activated by daily treatment with OCA for 7 days, and liver injury was induced by additional treatment with ANIT for the last 2 days (Figure 5A). Here, BRD4 is linked to infection.