BRD4 and autoimmune hepatitis: In this study, we obtained the following major novel findings: (1) Hepatic BRD4 expression was up-regulated in patients with liver fibrosis of various etiologies, including HBV, HCV, AIH, PBC, cholestasis, and overlap syndrome; (2) Hepatic BRD4 expression was positively correlated with the severity of liver fibrosis; (3) Increased expression levels of hepatic BRD4 were positively correlated with the circulatory parameters associated with hepatic functions in HBV-induced liver fibrosis.