Recent studies demonstrated that FUN14 domain containing 2, a mitochondrial protein which is upregulated in human hepatocellular carcinoma, interacted with and inhibited the GTPase domain of MFN1, resulting in the suppression of mitochondrial fusion.406 It was also proved that downregulation of Mfn2 occurs in conditions such as liver cancer, non-alcoholic steatohepatitis, and liver fibrosis.407–410 Aerobic exercise may benefit the restoration of Mfn2 levels in liver mitochondria and promote fatty acid oxidation, then alleviating the symptoms of non-alcoholic fatty liver disease.411. The gene discussed is MFN2; the disease is hepatocellular carcinoma.