EGFR and head and neck squamous cell carcinoma: Despite our ability to design chimeric, humanised or fully human antibodies with exquisite selectivity for a precisely designed target (EGFR) and the clear demonstration that these agents mediate a therapeutic effect in SCCHN, we are apparently no closer to defining biomarkers to predict which patients with this disease will and will not respond to anti-EGFR monoclonal antibody targeted therapy.