A previous study by Furuta T. et al. in Japan, in 2007 conducted on 313 adult patients with gastritis and peptic ulcer, found that the success rate of the H. pylori treatment in the patient group with MDR1 3435T/T genotype was 67%, which was statistically significantly lower than in MDR1 3435 C/C and 3435 C/T genotypes were 82% and 81%, respectively (p = 0.004) [3]. This evidence concerns the gene ABCB1 and peptic ulcer disease.