S100A8 and peptic ulcer disease: The Cag pathogenicity island (PAI) has been shown to be involved in persuading inflammation, ulceration and carcinogenesis.14 The cagA gene has been detected in the specimens taken from the severe cases of peptic ulcer.10-14 Genotyping using these virulence markers is considered as one of the best approaches for study of correlations between H. pylori isolates from different samples.