IRF4 and Stroke: During aging, primed microglia express higher levels of interferon regulatory factor (IRF)5 and lower levels of IRF4; these proteins regulate an inflammatory axis during stroke induced by middle cerebral artery occlusion (MCAO), which comes into detrimental effects in mice, also validated with its transgenic knockout IRF4 and IRF5 variants (Ngwa et al. 2022).