TNF and Parkinson disease: In studies by Chen et al. [53] it has been shown that the activity of microglia in vitro is modulated by TGF-β1, decreasing TNF-α, IL-1β, NO or rective oxygen speciesproduction induced by 1-methyl-4-phenylpyridinium (MPP+) dopaminergic neuronal loss in the rat model of PD.