TGF-β pathway is activated at early stages of fibrosis in Mdr2^−/−/p19^ARF−/− and Stat3^Δhc/Mdr2^−/− mice.

<p>60x histological sections of livers from control or 2 or 7 weeks-old Mdr2^−/−/p19^ARF−/−<i>(A)</i> and Stat3^Δhc/Mdr2^−/− mice <i>(B)</i> were stained with phospho-Smad2 or Smad7 and the number of positive cells was quantified. Left graph: positive nuclei for phospho-Smad2 with low or high signal intensity. Right graph: positive nuclei for Smad7. Data represent the mean ± SEM of cells in at least ten different fields. Student's t test calculated versus control sections (*p<0.05; **p<0.01;***p<0.001).