In a preclinical study investigating the role of a CB2 receptor agonist on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity in a mouse model of PD managed in 2017, the use of a CB2 agonist reversed the depletion of CB2 and thus increased the levels of dopamine and improved the behavior of PD mice (Shi et al., 2017). This evidence concerns the gene CNR2 and Parkinson disease.