In cerebral ischaemia‐reperfusion injury, oxidative stress is a major mechanism that aggravates the brain damage.8, 9, 10 Ischaemia and reperfusion can lead to a surge in free radicals, and the biosynthesis of nitric oxide is a key player in the pathophysiological response.13 Nitric oxide, synthesized by NOS from l‐arginine, is a very active gas free radical. The gene discussed is NOS2; the disease is injury.