ACACB and hydrops fetalis: Similarly, expression of the Acacb gene, which encodes Acc2 and results in raised malonyl-CoA, causing inhibition of Cpt1a, the rate-limiting step in FA uptake into mitochondria, was increased by the HF diet in Nrf2+/+ livers and to a much greater extent in HF-fed Nrf2−/− livers.