There was no significant difference in age or sex between the PD group and the control group (65 (57, 68) vs. 60 (56, 65), P = 0.068; 55.55% vs. 53.75%, P = 0.92), but the plasma SIRT1 level in the PD group was significantly lower than that in the normal control group (P = 0.025) (Fig. 1). The gene discussed is SIRT1; the disease is Parkinson disease.