S100A8 and Peptic ulcer: Previously, from 63 H. pylori strains isolated from Chilean patients without differentiation of geographical location, the cagA gene and the s1 m1 allelic variants of the vacA gene had a prevalence of 52%, being more common in patients with peptic ulcers than in strains isolated from patients with non-ulcer dyspepsia (26%) (p = 0.035) [45].