BRD4 and infection: To examine whether hepatic BRD4 has a novel function in BA regulation, BRD4 was downregulated specifically in the liver (BRD4 liver knockdown; BRD4-LKD mice) by infection of BRD4-floxed mice with hepatocyte-targeting AAV-TBG-Cre (refs. 5, 34; and Figure 1A).