This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Elucidate, through the cooperative effort of a multidisciplinary and multicenter group of collaborators, the etiology, natural history, diagnosis, treatment and prevention of nonalcoholic fatty liver disease (NAFLD) and in particular its more severe form of NASH and its complications. Construct a database of a large cohort of patients with NAFLD with a broad range of severity, recruited by the network. Core data collection will include clinical, demographic, laboratory, imaging and histological features. Develop a tissue bank comprising serum, liver tissue, DNA and urine obtained from recruited patients. Undertake Phase 2 and 3 trials of new approaches to the therapy of NAFLD in non-diabetic and diabetic patient subgroups. Provide a resource for developing clinical and pathological criteria for standardizing diagnotsic and staging criteria for NAFLD, provide a resource for developing clinical and pathological criteria and best measures and endpoints for therapeutic studies of NAFLD, provide a resource for ancillary studies of the pathogenesis, natural history and treatment of NAFLD, and initiate phase 3 trials of promising therapies for NAFLD.