S100A8 and peptic ulcer disease: The pathogenic mechanism of H. pylori may be related to many pathogenic factors of the bacteria, such as genes encoding outer membrane proteins (babA, oipA, sabA, and hopQ), exercise genes (flaA and flaB), and iceA, of which the CagA, VacA, activating protein A of peptic ulcer, and adhesins are particularly important (Da Costa et al., 2015).