NOS2 and Parkinson disease: Interestingly, it was demonstrated that microglial inducible nitric oxide synthase (iNOS) as well as IL-1β levels is increased in the brain of patients suffering from Parkinson's disease (PD) [4], leading to the hypothesis that the increased levels of iNOS or IL-1β may contribute to the pathophysiology of neurodegenerative disorders, especially for PD [5].