We have previously shown that specific MMP-9 inhibition with a monoclonal antibody reduces primary tumor growth and metastasis in a xenograft model of CRC.[32] The anti–MMP-9 antibody has been previously shown to specifically block pro–MMP-9 activation and MMP-9 enzymatic activity while potentially leaving the nonenzymatic signaling activity of MMP-9 intact.[46] However, antitumor immune response could not be investigated in the CRC model due to the impaired adaptive immune system of the nude mice. Here, MMP9 is linked to colorectal carcinoma.