IL1B and Stroke: To further investigate the underlying cell-type-specific IL-1 effects, we subjected IL-1 (α/β) knockout (Il1−/−) and wildtype (WT) littermate mice to permanent middle cerebral artery occlusion (pMCAO) and assessed immune cell infiltration and cytokine production in the ischemic hemisphere by flow cytometry 24 h and 72 h after stroke.