CPT1B and hydrops fetalis: The β-oxidation gene, Cpt1b, the TCA cycle gene Acss2, and electron transport chain genes, Atp5a1 and Cox5a, were increased by Sort1 deficiency in female Ldlr−/− BAT following a 15-week HF/HC diet (Fig. 3d); suggesting increased utilization of fatty acid for energy production in mitochondria.