TP53 and Familial adenomatous polyposis: Changes in tumor suppressor genes (e.g., APC, TP53: tumor protein 53) and oncogenes (e.g., KRAS: Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) can cause CRC, while FAP is caused by inherited germline mutations in the APC gene, which is located on chromosome six.