An important step to control biological activity of TGF-β is its activation referred as “TGF-β activation.” Proteolytic activation of latent TGF-β1 was first described in 1988 (Lyons et al. 1988) and was demonstrated in hepatic stellate cells during the pathogenesis of liver fibrosis and/or impaired liver regeneration in animal models (Okuno et al. 2001; Akita et al. 2002). Here, TGFB1 is linked to Hepatic fibrosis.