SNCA and Parkinson disease: α-Synuclein in oligomerized or aggregated form is known to be released outside from the neurons packed in extracellular vesicles (EVs), and such EVs may be responsible for the neuron-to-neuron transfer of α-synuclein and the spread of PD pathogenesis in the brain (Lööv et al., 2016; Yu et al., 2020).