S100A8 and infection: For example, in a long-term follow-up cohort, infection with strains that are simultaneously cagA-genopositive and vacA s1/m1 was associated 4.8-fold risk of progression of gastric precancerous lesions compared to those infected with cagA-negative/vacA s2/m2 strains, which was higher than each of the virulence factors considered alone (OR = 2.28–3.38) [38].