Early deletion of β-catenin in developing liver impairs hepatic morphogenesis but is compatible with biliary differentiation. Embryos with inactivation of β-catenin starting around E10.5 (Foxa3-Cre/βCatKO) showed perturbed liver architecture and differentiation of hepatocytes at E17.5; the number of HNF4α+ cells (arrowheads) was reduced. Biliary cells expressed the expected biliary markers but formed an increased number or irregularly-shaped luminal structures. βCat, β-catenin; Ecad, E-cadherin; hd, hepatic duct; OPN, osteopontin; pv, portal vein; *, lumen of ductal structure; scale bar, 100 μm.