FMO5 and Parkinson disease: In this study, we characterized the involvement of NADPH oxidase (Nox), a multisubunit enzyme that catalyzes the reduction of oxygen, in the 6-hydroxydopamine- (6-OHDA-) induced PD mice model and compared for the first time the effects of this neurotoxin in mice lacking gp91phox−/−, the catalytic subunit of Nox2, and pharmacological inhibition of Nox with apocynin.