The induction of parkinsonian symptoms was observed in PD animal models by the use of a neurotoxin that increased NADPH expression and microglia activation; moreover, increased expression of NADPH:quinone oxidoreductase was observed in the substantia nigra pars compacta of PD patients, among whom many were described as having dementia [8, 9]. This evidence concerns the gene NQO1 and Parkinson disease.