RTN4 and Parkinson disease: Receiver operating characteristic (ROC) curve analysis demonstrated that CSF levels of RTN4 may significantly discriminate AD patients from controls (AUC = 0.995, p < 0.001) and AD from PD (AUC = 0.958, p < 0.001) similarly like the commonly used AD biomarkers (tau—AUC = 0.895 and AUC = 0.984, pTau181—AUC = 1.00 and AUC = 0.926, Aβ1-42/Aβ1-40 ratio—AUC = 0.976 and AUC = 0.932).