NOS2 and Parkinson disease: To support the hypothesis that mitochondrial dysfunction observed in mesencephalic and striatal neurons might trigger neuroinflammation during the late PD progression, further experiments were performed in 16-month-old A53T-α-syn and WT mice with the aim to evaluate the expression levels of pro-inflammatory proteins, such as the inducible nitric oxide synthases (iNOS) and the Interleukin 1 beta (IL-1β).