They had all been shown to be negative for mutations in either the mismatch-repair genes, MSH2, MLH1, MSH6 and PMS2 and/or APC and MUTYH. No mutation in POLE was found in any of these patients, and it was concluded that mutations in this gene only is responsible for a minor fraction of inherited CRC in our region. This evidence concerns the gene MLH1 and colorectal carcinoma.