MMP9 and ulcer disease: This study investigated if the H. pylori dupA genotype and certain host single nucleotide polymorphisms (SNPs) of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs), including MMP-3, MMP-7, MMP-9, TIMP-1 and TIMP-2, might correlate with ulcer risk of H. pylori-infected Taiwanese patients.