In A2AR gene KO groups, treatment with l-DOPA (LID group) can significantly increase the mRNA expression of both GAD65 (sham: 1.05 ± 0.07; PD: 1.25 ± 0.11; LID: 1.55 ± 0.57) and GAD67 (sham: 0.85 ± 0.05; PD: 1.12 ± 0.12; LID: 1.63 ± 0.10) (n = 4, Ftreatment = 11.23, P < 0.05 vs. PD group or sham group, ANOVA and followed by LSD post hoc analysis, Figure 2). This evidence concerns the gene ADORA2A and Parkinson disease.