DIO1 and fatty liver disease: However, some DEGs that are positively associated with hepatic steatosis such as deiodinase 1 (Dio1) [63], are downregulated in the Efcab4b−/− livers, in addition the histological staining of the livers from Efcab4b−/− or WT mice did not show any pronounced lipid accumulation (in this particular study).