The schematic depicts the cellular phenotype and intracellular events in hereditary colorectal cancer (CRC) development. Hereditary CRC syndromes are caused by pathogenic variants in many different genes, which affect different molecular pathways in each hereditary syndrome. APC, adenomatous polyposis coli; FAP, familial adenomatous polyposis; IHC, immunohistochemistry; MAP, MUTYH-associated polyposis; MMR, mismatch repair; MSI, microsatellite instability; MSS,: microsatellite stability PPAP, polymerase proofreading-associated polyposis; SPS, serrated polyposis syndrome.