UCHL1 and Parkinson disease: Plasma UCHL1 levels were significantly higher in PD patients at H&Y stage >2, compared to controls (8.32 vs 3.61 pg/ml, p= 0.001) and mild PD patients at H&Y stage ≤2 (8.32 vs 4.36 pg/ml, p< 0.001), adjusted for age, gender and multiple comparisons.