Importantly, these results were confirmed in serum of mice injected with 1-methyl-1-4-phenyl-1,2,3,6-tetrahydripyridine hydrochloride (MPTP), and further validated in patients with idiopathic PD (iPD) and those harboring mutations in LRRK2 (LRRK2-PD), thus corroborating potential clinical relevance. This evidence concerns the gene LRRK2 and Parkinson disease.