RASD2 and Parkinson disease: Consistent with observations drawn from rodents, Napolitano and coworkers also reported a significant reduction of Rhes mRNA levels in the striatum of both 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated non-human primates (Macaca mulatta) and Parkinson’s disease (PD) patients [20].