DDC-treated mice livers showed the typical onion skin type-like periductal fibrosis as from 1 week of treatment (Fig. 8A), whereas Mdr2-/- mice showed mild cholestasis and mild age-dependent increase in periductular extracellular matrix deposition, as previously reported (Fig. 8F) (20, 36). Here, ABCB4 is linked to cholestasis.