In the acute stage of cerebrovascular disease, endothelial NOS and neuronal NOS are induced and their activity would be up-regulated after cerebral ischemia, whereas inducible nitric oxide synthase (iNOS) is activated to produce and release a large number of pathologic inflammatory factors that play an important role in necrosis and apoptosis of neurons. This evidence concerns the gene NOS2 and Cerebral ischemia.