Microglia is regarded as the resident macrophage-like cell in the CNS, and can be activated by brain injury, infection, and various neuroinflammatory stimuli, consequently releasing proinflammatory and cytotoxic factors including nitric oxide (NO), TNF-α, interleukin-1β (IL-1β), interleukin-6 (IL-6), ROS, and eicosanoids [65,66,67,68,69]. The gene discussed is IL6; the disease is infection.