TLR4 and Parkinson disease: This beneficial effect should be ascribed to the ability of GM to modulate microglia and astrocyte activation in SN by regulating the TLR4/NF-κB pro-inflammatory pathway and reducing the expression of GSK3β, iNOS and IL-1β, which are implicated in PD pathogenesis and progression [469,470,471,472,478,479,480].