It should be noted, however, that a more recently published non-clinical study of multiple animal models of IBD failed to demonstrate a beneficial effect of peptide inhibitors of MMP9, and MMP9 knockout mice did not differ from wild-type mice in disease severity of DSS- or 2,4,6-trinitrobenzenesulphonic acid-induced colitis.42 Furthermore, a recent phase 2 trial of andecaliximab in Crohn’s disease yielded similar negative results [see companion paper]. Here, MMP9 is linked to Crohn disease.