PG considered as the major products of COX-1 and COX-2 activity, are regarded as classic mediators of cytoprotection and when applied exogenously in the non-antisecretory doses, they are able to prevent the mucosal damage induced by necrotizing substances (e.g. absolute ethanol) [47, 48] and contribute to mechanisms of gastroprotection, gastric adaptation to damaging agents and the healing of acute and chronic ulcerations [49–51]. This evidence concerns the gene PTGS1 and ulcer disease.