S100A9 and gastritis: When comparing the frequency of the 520 selected alleles between the isolates from subjects with gastritis and isolates from subjects with IM or GC we found statistically significant differences in allele distribution for three polymorphisms in cagA gene (Q/K427R, N467G and V1041T), three in cagC gene (V22I, V37I, I45V), one in the cagE gene (K981E), one in cagL gene (S10F), one in cagX gene (G11N), one in cagS (G146D), one in cagζ (S35A), three in cagδ (V353I, P406L, N407E) and one in cagβ (N125A) (Table 2).