TNF and brain ischemia: NF-κB is a ubiquitous transcription factor that regulates a number of genes involved in inflammation and immune response, which is normally sequestered in the cytoplasm where it associates with a family of inhibitory proteins known as IκB. Activation of NF-κB after cerebral ischemia induced expression of proinflammatory genes including TNF-α, IL-1β, and COX-2.