THY1 and fibrosis: In contrast to Msln−/− mice with BDL- or Mdr2−/−-induced cholestatic fibrosis, Thy1−/− mice developed more advanced fibrosis by ≈25%, which was associated with increased numbers of Col-GFP+CD34+ aPFs with significant upregulation of Col1a1, αSMA, TGFβRI, and Msln genes, supporting the inhibitory effect of Thy1 on activation of aPFs [14,17].