This corresponds to the following surface areas: 24.9 cm2 mucosa from Lynch syndrome mutation carriers (22.5 cm2 large bowel, 2.4 cm2 small bowel) and 5.1 cm2 from patients without an MMR gene germline mutation (4.7 cm2 large bowel, 0.4 cm2 small bowel), including 2.2 cm2 from sporadic MSI-H colorectal cancer patients (1.8 cm2 large bowel, 0.4 cm2 small bowel). This evidence concerns the gene MRC1 and Lynch syndrome.