S100A8 and gastritis: Umit et al. (2009) found that high cytotoxin-associated antigen A (CagA) positivity in H. pylori strains is associated with more severe gastritis, according to some histological features of the disease. H. pylori genotypes also differ significantly among populations in different regions; for instance, a greater prevalence of VacA, CagA+, and BabA2− genotypes is observed in patients with chronic gastritis in southern Mexico (Atrisco-Morales et al., 2018).