One of the first studies performed on the blood of pwPD to verify the actual potential of EVs as biomarkers of PD was attempted by Shi and colleagues, who demonstrated that both plasma exosomal α-syn [48] and tau [45] correlated with PD severity, performing even better than the quantification of free α-syn or tau in cerebrospinal fluid (CSF). Here, MAPT is linked to Parkinson disease.