Conversely, when DRD3 expression was evaluated after ex vivo T-cell activation, DRD3 expression was significantly reduced in total CD4+ T-cells (CD3+ CD4+) and in memory/effector CD4+ T-cells (CD3+ CD4+ CD45RO+) obtained from PD patients (Figure 1A, right panel). This evidence concerns the gene DRD3 and Parkinson disease.