TNF and Parkinson disease: In general, aggregated proteins such as Aβ, α-synuclein, and mHtt associated with AD, Parkinson’s disease (PD), and Huntington’s disease (HD) respectively, can activate microglia and release amounts of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), nitric oxide (NO), and reactive oxygen species (ROS).