As total α-synuclein levels were also increased in patients with PD compared to controls (p < 0.001, Figure 1B), the plasma total α-synuclein cut-off of 119.5 fg/mL also had satisfactory sensitivity of 86.3% and specificity of 93.5% for distinguishing between patients with PD and controls (AUC 0.91; Figure 2). The gene discussed is SNCA; the disease is Parkinson disease.