 Non-alcoholic Fatty Liver Disease NAFLD is an alcohol-like liver disease that occurs in individuals who do not consume excessive alcohol. Similar to alcohol-induced liver disease, NAFLD encompasses a spectrum of liver damage, ranging from non-alcoholic fatty liver NAFL on the most clinically benign end of the spectrum to cirrhosis on the opposite extreme where most liver-related morbidity and mortality occur. In NAFL, the liver is steatotic but generally healthy. Nonalcoholic steatohepatitis NASH is a more severe form of liver damage than NAFL because there is increased hepatocyte death in addition to steatosis. The liver injury in NASH triggers a repair response that sometimes leads to cirrhosis.1-3 The architecture of cirrhotic livers is distorted by regenerating nodules and fibrous tissue. Cirrhosis results when fibrosis disrupts the normal liver architecture, carving the parenchyma into nodules of hepatocytes that are separated from each other by bands of connective tissue. Some individuals with NAFLD develop cirrhosis. As in other types of liver disease, progression to this advanced stage of liver damage from NAFLD is generally thought to require many years, perhaps decades. Because most liver-related morbidity and mortality occur in cirrhotic individuals, researchers are trying to understand the basis for inter-individual differences in the tendency to develop cirrhosis. Exiting blood tests and imaging modalities have limited sensitivity for detecting liver steatosis, steatohepatitis and cirrhosis. In addition, there is no test that can distinguish NAFLD from other causes of fatty liver disease. Thus, at the present time, NAFLD is a diagnosis of exclusion. 