Exon 2 (codon 12, 13), 3 (codon 59, 61) and 4 (codon 117, 146) KRAS and NRAS mutations occur in 50–55% of CRC patients [7], where they have been associated with resistance to EGFR-targeted therapies and poor survival [8, 9]. This evidence concerns the gene EGFR and colorectal carcinoma.