The ROC curve of TNF-α for the diagnosis of PD showed AUC was .719 (p < .05, 95% CI: .655–.784), indicating that TNF-α has a good diagnostic value for PD, and the critical value of TNF-α for the diagnosis of PD was 5.380 pg/ml, with a diagnostic sensitivity of 76.0% and a specificity of 59.3% (Figure 2). Here, TNF is linked to Parkinson disease.