HNF4A and hyperlipidemia: Data in this study indicate that HNF4α antagonizes the transactivation of SREBP-1C by LXR to control hepatic lipid metabolism, and thus establishes partial deficiency of HNF4α as a key mechanism of the dysregulation of the two master lipogenic factors LXR and SREBP-1C during hepatosteatosis and hyperlipidemia.