Description:This project aims to further understand about how the environment impacts nonalcoholic fatty liver disease NAFLD and nonalcoholic steatohepatitis (NASH) in children. At present the NASH CRN has the largest, well characterized cohort of children with NAFLD, including clinical data, labs, cytokines, genetic polymorphisms, but no proteomics, metabolomics, lipidomics or toxicant assessment. Exposure and untargeted metabolomics analyses will examine the role of environmental toxicants in modulating disease severity and the endogenous response to exposures in children with NAFLD.