These data suggested that in Mongolia, where the incidence of gastric cancer death is the highest worldwide, most strains were either cagA-negative or Western-type cagA. Therefore, it will be impossible to explain the virulence only by the genotypes of cagA alone or even by the combination of cagA with well-known virulence factors such as vacA. Since H. pylori contains approximately 1,500 genes, other unknown virulence factors of H. pylori might play important roles in its pathogenesis in Thailand. Here, S100A8 is linked to gastric cancer.