SMAD3 and Hepatic fibrosis: In addition to necroinflammation induced by HBV and HDV infections, the findings of the currently study indicate that the activation of Twist and TGF-β via the specific binding of L-HDAg and SMAD3 may contribute to EMT and the accelerating liver fibrosis that appears to be a characteristic finding in HDV infection [2, 3, 26].