TIMP1 and duodenal ulcer: However, because TIMP-1 genotypes may modulate MMP-3 activity, further testing if the MMP-3-1612 /TIMP-1372 Combined genotypes contribute to increased risk of duodenal ulcers shows that the combined MMP-3/TIMP-1 genotype as 6A6A/CC has a 3.6-fold increased risk of duodenal ulcer (p < 0.05) in H. pylori-infected females.