Unlike patients with HNPCC, who develop only a few adenomas, people with FAP syndrome characteristically develop hundreds of polyps at a relatively young age; one or more of these adenomas typically undergoes a malignant transformation as early as age 20; FAP, connected with APC-associated polyposis, is inherited in an autosomal dominant manner (75–80% of individuals have an affected parent) and accounts for less than 1% of all CRC cases [55]. This evidence concerns the gene APC and hereditary nonpolyposis colon cancer.