CD63 and Parkinson disease: In this study, PD patients show significantly increased expressions of sEV markers (CD9, p = 0.0004; CD63, p = 0.0017; Flotillin-1, p = 0.0213), a neuronal marker (L1CAM, p = 0.0253) and PD specific phospho-α-synuclein (p = 0.0093) than healthy controls due to higher numbers of sEV in PD patients as observed in the NTA experiments.