Nonalcoholic fatty liver disease(NAFLD),a progressive disease that begins with simple steatosis,may develop to nonalcoholic steatohepatitis(NASH)and fibrosis.NAFLD is the most commonly chronic liver disease in the worldwide currently.In countries with a Western diet containing a high fat and/or cholesterol content,NASH and hepatic fibrosis are widely prevalent.However,the underlying mechanism of how NAFLD progresses to hepatic fibrosis is poorly understood.