NOS3 and ischemic stroke: We had previously demonstrated that polymorphism Glu298Asp in the endothelial nitric oxide synthase (eNOS) gene (p = 0.001) [26] and the C677T in the methylenetetrahydrofolate reductase (MTHFR) (p = 0.001) [27] were associated with an increased risk for ischemic stroke in the same group of patients.