TNF and juvenile Huntington disease: However, aberrantly activated microglia can bring about the release of various pro-inflammatory cytokines and mediators, including nitric oxide (NO), prostaglandin E2 (PGE-2), reactive oxygen species (ROS), interleukin (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α), which are closely related to neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), multiple sclerosis, Huntington’s disease, and stroke [3,4,5,6].