Study subjects had to be either proven carriers of pathologic mutations in MMR genes or have family members with Lynch syndrome and have had at least one of the following: colorectal cancer, a related carcinoma, an adenoma of over 5 mm in diameter, an adenoma at younger than 40 years old, or a confirmed adenoma of any size at more than 1 endoscopy. This evidence concerns the gene MRC1 and adenoma.