EGFR and metastatic colorectal cancer: The therapeutic approach to metastatic colorectal cancer (mCRC) has changed in recent years, mainly thanks to the introduction of biologic drugs such as cetuximab, a monoclonal antibody (MoAb) directed against the epidermal growth factor receptor (EGFR), or bevacizumab, a MoAb that blocks the vascular endothelial growth factor (VEGF) [1].