TNF and brain ischemia: During the subacute phase of cerebral ischemia, astrocytes release S100B, which interacts with the receptor for advanced glycation end products (RAGE) to stimulate the microglial secretion of proinflammatory cytokines, such as interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), by activating nuclear factor-κB (NF-κB).