TLR4 and Parkinson disease: TLR4 has been found to play important role in α-synuclein-induced microglia activation in vitro.303 The absence of TLR4 can reduce neuroinflammation through multiple pathways in an MPTP-induced PD mouse model.304 TLR4 antagonists significantly reduce the death of primary neurons co-cultured with glial cells, indicating the involvement of TLR4-mediated glial cell activation in α-synuclein oligomer-induced neuronal death.305 However, Venezia et al.’s study yields a conflicting result.