TNF and brain ischemia: Astrocytes during cerebral ischemia mainly activate NF‐κB, signal transducers, and the STAT3 pathway to induce inflammatory cytokines (IL‐6, IL‐1α, IL‐1β, TNF‐α, and interferon‐γ, among others) and release neurotoxic mediators (including NO and ROS), leading to neuronal damage and death.63