The Snai1 family is not involved in intrinsic dedifferentiation and caveolin-1 upregulation. (A) Snai1 is slightly upregulated during dedifferentiation and tremendously and time dependently induced by TGF-β1 stimulation (**p < 0.005 at all time points when comparing untreated with TGF-β1; p < 0.05 untreated d3 vs. untreated d1). (B) No change of Snai2 (Slug) expression could be detected in hepatocytes cultured for 4 days. Beginning on day 3, TGF-β did increase its expression (p ≤ 0.002 at d3 and d4 comparing expression of untreated vs. TGF-β1). (C) Dedifferentiating hepatocytes from wild type and Snai1 ko mice were analyzed for dedifferentiation events with Western blot. No alterations in ERK activation and caveolin-1 induction were observed. (D) Proof of hepatocyte specific Snai1 knockout. Basal Snai1 expression was very weak in wild type hepatocytes (based on qPCR data) and almost absent in Snai1 ko hepatocytes. Induction of Snai1 expression was triggered by TGF-β1 stimulation for 6 h. Control hepatocytes responded with strong induction, whereas Snai1 knockout hepatocytes did not induce expression (p < 0.001).