The sequence FPLKRHDKVDDLSKV found in western type CagA (WSS) is replaced by sequence KIASAGKGVGGFSGA in East-Asian type CagA (ESS) and this variation in amino acid sequences might be the reason behind the high prevalence of gastric cancer in Japan as compared to the West [25,30,33]. This evidence concerns the gene S100A8 and gastric cancer.