MMP3 and inflammatory bowel disease: The MMP-3 -1613 5T5T genotype was significantly more frequent in CD patients who developed strictures, compared to the other MMP-3 -1613 5T6T/6T6T genotypes.26 The MMP-3 protein also seems to be more highly expressed in IBD tissue carrying the 5T5T variant of the MMP3 gene compared to 5T6T/6T6T genotypes, but this was not significant.26,27