SNCA and Parkinson disease: The expression of a PD-linked gene encoding α-synuclein (α-syn) in dopaminergic neurons of Drosophila [222], overexpression of human wild-type α-syn within murine SNpc [223], and toxin-based models by injection of 6-hydroxydopamine [224] and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine [212,223,225,226] were used to mimic in vivo PD.