The term nonalcoholic fatty liver disease (NAFLD) covers a pathologic spectrum from lipid accumulation alone (simple steatosis) to steatosis with associated inflammation and fibrosis (nonalcoholic steatohepatitis [NASH]). Nonalcoholic steatohepatitis can progress to cirrhosis and potentially to hepatocellular carcinoma. Although a genetic predisposition has been highlighted, NAFLD is strongly associated with an unhealthy lifestyle and hypercaloric diet in the context of obesity and metabolic disease. The dysregulation of specific pathways (insulin signaling, mitochondrial function, fatty acid, and lipoprotein metabolism) have been linked to steatosis, but elucidating the molecular events determining evolution of the disease still requires f...