SNAP25 and Parkinson disease: Receiver operating characteristic curves analyses were used to examine the accuracy of the six potential biomarker genes to diagnose PD, with AUC values of 0.896 (GAP43), 0.837 (GRIA1), 0.775 (NEFL), 0.762 (NEFM), 0.740 (SNAP25), and 0.890 (SYT1), respectively, in the training set (Figure 7A).