HP and chronic atrophic gastritis: AMOVA, applied to all the Hp genotypes found in the GINs and in the various NNGDL subsets (non-atrophic gastritis, non-atrophic gastritis associated with gastric erosions, and non-atrophic gastritis associated with duodenal ulcer), showed that “within-groups” variance was 97.49% for both vacA s and m, and 95.33% considering only vacA s.