In addition to the total and aggregated α-syn, biomarker studies on other α-synucleinopathy-related proteins in AEVs, including phosphorylated α-syn, DJ-1, and neurofilament light chain, which have shown biomarker potential in the CSF and blood [59, 60], may contribute to the diagnosis and differential diagnosis of PD. Here, NEFL is linked to synucleinopathy.