It was also found that Y39 is preferentially nitrated (nY39) in a cell model of Parkinson's disease overexpressing monoamine oxidase B (MOA-B), an enzyme involved in dopamine metabolism and known to create reactive oxygen species, and that this effect can be abrogated using selegiline, an inhibitor of MOA-B approved for the treatment of Parkinson's disease (186). This evidence concerns the gene MAOB and Parkinson disease.