Of the three synuclein proteins, α-synuclein has been the most studied due to its higher abundance in the brain and because of the discovery of its link to the pathogenesis of PD and later to the development of many other neurodegenerative diseases collectively known as synucleinopathies [17,18,19,20,21,22,23]. Here, SNCG is linked to neurodegenerative disease.