Furthermore, it was recently demonstrated that PDGF-β plays a role in the trans-differentiation processes of HSCs into an activated phenotype, and that administration of an anti-PDGF-β antibody (MPR8457) inhibits development and progression of biliary fibrosis in Abcb4 KO mice, which serve as a chronic model for sclerosing cholangitis [56,57]. The gene discussed is ABCB4; the disease is sclerosing cholangitis.