National Comprehensive Cancer Network (NCCN) guidelines state that all patients with metastatic CRC should have tumor tissue genotyped for KRAS, NRAS, and BRAF V600E mutations, and any patient with a known KRAS or NRAS mutation should not be treated with anti-EGFR therapy such as cetuximab and panitumumab7. This evidence concerns the gene KRAS and neoplasm.