IL17A and ischemic stroke: Proinflammatory cytokines such as IL‐1β, TNF‐α, and IL‐6 are critical for promoting bacterial clearance during lung infections.19, 20 IFN‐γ and IL‐17A are signature cytokines of Th1 and Th17 cells, both of which support innate‐cell activation and migration.21, 22 We found that the levels of IL‐1β, TNF‐α, IFN‐γ, IL‐17A, and IL‐27 were reduced 72 hours following ischemic stroke (Figure 9A‐E).