Single MMP-9−/− and double MMP-2−/−/MMP-9−/− mice were claimed to be resistant to the development of acute colitis induced by dextran sodium sulphate (DSS)6, 7, 8 and monoclonal antibodies against MMP-9 were used to block acute DSS-induced colitis in mice9, 10. The gene discussed is MMP9; the disease is colitis.