S100A8 and gastric cancer: Western CagA strains usually include EPIYA-a, EPIYA-b and EPIYA-c sequences, while East Asian CagA strains only have EPIYA-a, EPIYA-b and a specific EPIYA-d, which can be partly explained by the highest incidence of gastric cancer in East Asian countries (Vianna et al., 2015; Kumar and Dhiman, 2018).