SNCA and neurodegenerative disease: Oxidative stress, mitochondrial dysfunction, impaired protein degradation, the post-translational modifications of α-synuclein, inflammation, defects in chaperone-mediated conformational control, increased calcium level and other deleterious events in neurodegenerative diseases are thought to be key factors evoking α-synuclein aggregation [17,18,19,20,21,22].