Both MMP-9-/- mice and WT littermates developed severe acute colitis after DSS administration with loss of body weight (Fig. 1a, b, c), higher disease activity index (DAI) (Fig. 1d), increased colon/weight length ratio (Fig. 1e), and elevated macroscopic damage score (Fig. 1f) compared to corresponding control mice. The gene discussed is MMP9; the disease is colitis.