Moreover, cardiac iron deficiency in HF was accompanied by reduced activity of aconitase and citrate synthase and reduced expression of ROS-protective enzymes (catalase, glutathione peroxidase, and superoxide dismutase 2), indicating that myocardial iron deficiency may contribute to the exacerbation of mitochondrial dysfunction that exists in HF (73). The gene discussed is CAT; the disease is hydrops fetalis.