Regarding liver fibrosis, which is a risk factor in the development of cirrhosis and HCC [75], high expression of MFN2 protein inhibits the Transforming growth factor beta 1/Smad (TGF-β1/Smad) signaling pathway, thus triggering the downregulation of type I, type III, and type IV collagen and reducing the formation of factors associated with liver fibrosis [76]. The gene discussed is MFN2; the disease is hepatocellular carcinoma.