Cetuximab, an IgG1 monoclonal antibody directed against the Epidermal Growth Factor Receptor (EGFR), has shown efficacy in combination with chemotherapy in patients with metastatic colorectal cancer (mCRC), although not in patients with KRAS mutations, [3], [4] which are seen in about 40% of the patients with CRC. Here, KRAS is linked to metastatic colorectal cancer.