In addition, elevated expression of macrophage-antigen complex 1 (Mac-1), a β2-integrin family member expressed exclusively in microglia, and NADPH oxidase (PHOX), one of the major sources for production of ROS or related reactive nitric species (RNS) in activated microglia, have been reported in PD animal models [8,11,13-16,22-35]. This evidence concerns the gene ITGAM and Parkinson disease.