In this study we found that knocking out MCPIP1 significantly enhanced the activation of JNK kinase and phosphorylation of c-jun in mouse brain after ischemic/reperfusion injury and that administration of the JNK inhibitor SP600125 reduced hyperphosphorylation of JNK and c-Jun signaling after cerebral ischemia and significantly decreased the production of proinflammatory cytokines such as TNFα and IL-1β. Here, TNF is linked to brain ischemia.