Several studies already noticed some connection between α-synuclein and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a well characterized neurotoxin for inducing PD models at present, which oxidized in vivo into the toxic substrate 1-methyl-4-phenylpyridinium (MPP+) [8], [9], [10]. This evidence concerns the gene SNCA and Parkinson disease.