tHN-C3 prevented neuronal cell death induced by H2O2 or soluble Aβ(1-42) via Bax binding; moreover, tHN-C3 could successfully prevent neuronal cell death and infiltration of inflammatory cells in the brain, while it improved cognitive memory in Tg2576 mice and in the rat middle cerebral artery occlusion model of stroke. The gene discussed is C3; the disease is Stroke.