TGFB1 and Hepatic fibrosis: Activation of HSCs and fibrogenic signaling, such as increased expression of αSMA and COL1A1 proteins and collagen secretion, were observed in the livers of 8- and 12-week-old STAM mice while pro-fibrogenic cytokines Tgfβ1/β2 were robustly induced at 12 weeks, demonstrating the presence of liver fibrosis (Fig. 5D; Fig. S4C, k & l; Fig. S4D, E).