S100A8 and gastroesophageal reflux disease: Thereby the cagE is an important marker of pathogenicity alone or combined with cagA (40).Since the impact of H. pylori and its virulence in GERD development is not yet well clear, so we aimed to evaluate the prevalence of H. pylori as well as its major Cag pathogenesity island markers including Cag A and Cag E gens in GERD patients compare to control group referring to Taleghani Hospital, Tehran, Iran.