Cheng found that glycolysis and Krebs cycle were significantly impaired and ATP was reduced in a Drosophila model of mitochondrial aconitase deficiency.11 Abela performed plasma metabolomics analysis of patients with ACO2 deficiency and showed that Krebs cycle metabolites were significantly reduced in these patients.38 Taken together, these data suggest that ACO2 plays an important role in the maintenance of mitochondrial function. The gene discussed is ACO2; the disease is hyperinsulinemic hypoglycemia, familial, 4.