One of them is the endothelial nitric oxide synthase (eNOS) that produces NO to assist gastric ulcer healing mainly through stimulation of blood vessels' formation, increasing blood flow, and anti-inflammatory action [11], while NO generated from inducible nitric oxide synthase (iNOS) functions in gastric ulcer induction via the formation of ROS and toxic effects on cells [12]. This evidence concerns the gene NOS3 and gastric ulcer.