TNF and ischemic stroke: The classical activated phenotype (M1) microglia are immediately activated after ischemic stroke and release robust inflammatory cytokines, such as interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and induced nitric oxide synthase (iNOS), which contribute to neuronal apoptosis and aggravate brain injury (Denes et al., 2007; Hu et al., 2012; DeGracia, 2013; Garden, 2013; Wang et al., 2013).