The epidermal growth factor receptor (EGFR) is a protein leads to the activation of intracellular pathways that act directly on cell function, changes and survival. Cetuximab (CTX) is an anti-EGFR monoclonal antibody approved for the treatment of patients with head and neck squamous cell carcinoma (HNC) and metastatic colorectal cancer (mCRC). The response of patients with mCRC to cetuximab has already been associated with wild-type KRAS, NRAS and BRAF.