EGFR and metastatic colorectal cancer: Cetuximab (Erbitux®), a recombinant human/mouse chimeric anti-EGFR monoclonal antibody, approved by the FDA in 2004, was the first monoclonal antibody targeting EGFR for patients with EGFR-expressing metastatic colorectal cancer after failure of both irinotecan- and oxaliplatin-based regimens or for those who are intolerant of irinotecan-containing regimens [7,8].