In Caucasian PD patients, we found that medicated patients have fewer CD4+ T cells (p=0.0018 Figure 6G), granulocytes (p=0.025 Figure 6O), and B cells (p=0.012 Figure 6Q) but more exhausted CD8+ T cells (p=0.019 Figure 6E). This evidence concerns the gene CD4 and Parkinson disease.