However, the marked hypolipidemia in chow-fed adult HNF4α KO mice sharply contrasts with the hyperlipidemia in patients and animal models with NAFLD/non-alcoholic steatohepatitis (NASH) in which HNF4α is partially lost [7, 8], a condition that may be better mimicked in mice with hetero-deficiency of HNF4α. This evidence concerns the gene HNF4A and metabolic dysfunction-associated steatohepatitis.