NPTX2 and Parkinson disease: Co-transfection of miR-221-3p mimic and wt-NPTX2-3’UTR resulted in decreased luciferase activity compared to PD cells treated with mimic NC (p < 0.05), but there was no difference in luciferase activity after co-transfection with miR-221-3p mimic and mut-NPTX2-3’UTR (p > 0.05) (Figure 4G).