Colon cancer represents one of the major causes of death in the Western hemisphere, being responsible for over 60,000 deaths per year in the U.S. Over the past 50 years, the hypothesis of the adenoma-carcinoma sequence, which proposes that benign colonic polyps are the precursor lesions of malignancy, has been accepted. Any study of the possible carcinogenic mechanisms in colon cancer therefore should also be directed to the precursor lesions - the benign polyps.