APC and colorectal carcinoma: However, a lower percentage of cases (about 30%) is represented by familial cases, of which approximately 5% present specific genetic signatures, penetrance, and transmission due to germline variants in CRC predisposing genes, e.g., adenomatous polyposis coli (APC), mismatch repair (MMR) genes, epithelial cell adhesion molecule (EPCAM), SMAD4/BMPR1A, and MUTYH (4–7).