In addition to having inflammation in the liver, overweight people also have changes in the composition of their immune systems and subsets of their immune systems. There are several genes involved in liver metabolism that have been implicated in nonalcoholic fatty liver disease (NAFLD), a liver disease associated with obesity, which is caused by high triglycerides and liver transaminases. NAFLD, a global liver disease, may differ in gene expression depending on where a person lives. In some alleles, the risk factors were independent. Finally, the researchers identified many genetic variations connected to fatty liver disease in those who did not drink alcohol regularly. These variants were located in genes involved in RNA metabolism, protein catabolism, and energy metabolism.