In the early stage of cerebral ischemia, TNF-α, IL-6, and IL-1β are activated as inflammatory factors downstream of the NF-κB signalling pathway, and high concentrations of TNF-α, IL-6, and IL-1β in turn activate the expression of NF-κB, which promotes the polarization of microglia towards the M1 phenotype and the expression of related chemokines. Here, TNF is linked to brain ischemia.