NOS2 and Parkinson disease: Several studies have demonstrated that intracerebral injection of AAV2-hIL-10 in MPTP-induced mouse models of PD could enhance the expression of the striatal tyrosine hydroxylase protein associated with down-regulated expressions of pro-inflammatory iNOS, and promote the production of anti-inflammatory factors like TGF-β, suggesting the neuroprotective properties of AAV2-hIL-10 (Schwenkgrub et al., 2013; Joniec-Maciejak et al., 2014).