The ROC analysis showed that the serum BDNF had a 78% sensitivity and an 81% specificity (AUC 0.82) in distinguishing between PD patients with RLS and without RLS, and had a 75% sensitivity and a 68% specificity (AUC 0.76) in distinguishing between PD with RLS and control with RLS. The gene discussed is BDNF; the disease is Parkinson disease.