When the expression of pro-inflammatory cytokines around the SN region was measured in PD mice, 6-OHDA induced an increase in IL-1α and IL-1β. Interestingly, F3-derived EVs treated with 6-OHDA showed that the levels of both cytokines were significantly downregulated, compared to the HFF-derived EV-treated group (Fig. 5F and G). The gene discussed is IL1B; the disease is Parkinson disease.