VGF and Parkinson disease: The levels of VGF C-terminal (C-t) peptides were analyzed by a home-made competitive ELISA using an antibody directed against the last nine amino acids at the C-terminus of human proVGF in PD patients at the time of diagnosis (drug-free, n = 23) or after dopamine replacement (n = 40) compared to age-matched controls (n = 21) [101].