MMP1 and inflammatory bowel disease: In general, it was found that TIMP-1 expression is increased in the fibrotic [both mucosa and muscularis] intestine compared to non-fibrotic CD intestine and non-IBD controls.55,66 Interestingly, MMP-1 and -14, as well as TIMP-1 expression, were significantly increased in full-thickness fibrotic terminal CD ileum when compared to non-fibrotic and non-CD controls.51 Warnaar et al. also found that MMP-1 and MMP-3 are upregulated in muscularis and submucosal tissue of the fibrotic intestine.