TLR4 and Cerebral ischemia: For instance, the study by Hwang et al. (2017) showed that sevoflurane postconditioning decreased the production of multiple proinflammatory cytokines such as TNF-α, IL-6, and IL-1β, via the Toll-like receptor-4/NF-κB pathway, which was activated by cerebral ischemia/reperfusion injury.