SOX9 and Hepatic fibrosis: In CCl4 or DEN/CCl4-induced liver fibrosis, co-immunofluorescene of YFP with ductal BECs markers (CK19, SOX9, OPN) demonstrated ductal metaplasia of hepatocytes into ductal BECs was diminished in DAPT-treated mice (Figs. 3d, f and S4B).