HNPCC is associated with pathogenic variants of the MLH1, MSH2, MSH6, PMS2 and EPCAM genes, and is also characterized by an increased risk of CRC, the pathological feature of which is the presence of mucinous adenocarcinoma (lifetime risk at 52–82%, mean age at diagnosis 44–61 years) [23,79]. This evidence concerns the gene PMS2 and hereditary nonpolyposis colon cancer.