Compared with that in NC mice, numerous microglia in the SN of PD mice were activated, and the proinflammatory cytokines IL-6, IFN-γ, TNF-α and IL-1β were significantly increased, while the anti-inflammatory cytokines IL-10 and TGF-β1 were significantly reduced (Fig. 2E-G). Here, TNF is linked to Parkinson disease.