The expression of MMP-7 (pump-1) gene was examined in 10 cases of colorectal cancer by utilizing RT-PCR. In 9 out of 10 cases, MMP-7 mRNA was detected in cancerous tissue, whereas none was detected in adjacent normal colon tissue. However, this message was detected in only 1 out of 6 colon-cancer cell lines. In colonic mucosa from 3 patients with ulcerative colitis it was not detected. The expression of MMP-2 (72-kDa type-IV collagenase) mRNA was also investigated in the same tissue samples, and was detected in all samples, including cancerous and non-cancerous tissue. Our data suggest that MMP-7 is expressed in a tumor-associated manner in colorectal cancers and may play a role in tumor progression.