NEFL and Parkinson disease: Using data from PD subjects with positive αSyn-SAA, we calculated correlation coefficients of kinetic parameters (Fmax, AUC, T50, TTT) versus multiple clinical motor (UPDRS), non-motor (RBDQ, SCOPA-AUT, MoCA, UPSIT), imaging (DAT-SPECT SBR), and biomarkers (CSF Aβ, tau, and NfL) (Additional file 1: Fig. S3, online resource).