TGFB1 and injury: Furthermore, in the murine models of chronic carbon tetrachloride- (CCl4-) induced liver injury and bleomycin-induced lung injury, hAEC therapies are reported to reduce the levels of profibrotic factors, namely, transforming growth factor-β (TGFβ) and platelet-derived growth factor (PDGF) [24, 36, 40].