A significant difference was found between the MSA and PD groups (p = 0.0356) in the parameter CoQ10/CS (level of coenzyme Q10 normalized to activity of citrate synthase) in lymphocytes (Figure 2C), whereby CS activity was significantly reduced in all three analyzed groups of patients and no difference of CS was found between the patient groups (Figure 2B). The gene discussed is CS; the disease is Parkinson disease.