KRAS and colorectal carcinoma: Regardless of BRAF, KRAS, or NRAS mutation status, ERBB2 amplification is also associated with inferior outcomes for patients with metastatic CRC treated with EGFR antibodies.45,46 In conclusion, alterations in all 4 of these genes need to be considered for decisions on treatment with approved EGFR antibodies or enrollment into clinical trials with HER2-targeted agents in CRC.