KRAS and colorectal carcinoma: It is widely known that mutations in the Kirsten rat sarcoma viral oncogene homolog (KRAS) gene occur in the early stages of the adenoma–adenocarcinoma sequence in human colorectal cancer (CRC) development.1KRAS, along with the neuroblastoma rat sarcoma viral oncogene homolog (NRAS) and Harvey rat sarcoma viral oncogene homolog (HRAS) genes, is a member of the RAS gene family.