The mitochondrial complexes I, II-III, IV and citrate synthase were measured in the regions frontal cortex, parietal cortex and putamen as previously described31 and it was found that all of the complex ratios I, II-III, and IV to citrate synthase were significantly different between the PD and control groups in the putamen region, with complex-ratios I and II-III lower in PD, and complex-ratio IV higher in PD (Supplementary Results Figure S5). This evidence concerns the gene CS and Parkinson disease.