GPT and Decreased liver function: Moreover, another study eliminated transforming growth factor-β (TGF-β) signalling by adenovirus-mediated expression of a dominant-negative type-II TGF-β receptor in a DMN-induced hepatic fibrosis rat model, and the results revealed that it could reduce ALT levels of the model control more than 60-fold, and the rats in the model control all died of liver dysfunction (31).