EGFR and colorectal cancer: Monoclonal antibodies (mAbs) have been developed for cancer treatment, including cetuximab (a mouse–human chimeric mAb; IgG1) against head and neck and colorectal cancers, panitumumab (a fully human mAb; IgG2) against colorectal cancers, and necitumumab (a fully human mAb; IgG1) against non-small cell lung cancers.(8–10) Anti-EGFR mAbs possess various functional mechanisms: antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), blocking dimerization, blocking ligand binding, and EGFR endocytosis.