In PD patients with early-stage disease duration (≤3 years), a correlation of serum SIRT2 concentration was noted with UPDRS part III motor score (r = 0.605, p = 0.0028), duration (r = 0.54, p = 0.0101) and H&Y stage (r = 0.41, p = 0.05; Figures 2A–C). The gene discussed is SIRT2; the disease is Parkinson disease.