ERBB3 and head and neck squamous cell carcinoma: Epidermal growth factor receptor (EGFR), a member of HER (ErbB) family tyrosine kinase receptors that includes EGFR (HER1/ErbB-1), HER2/neu (ErbB-2), HER3 (ErbB-3) and HER4 (ErbB-4) (4, 5), is overexpressed in up to 90% of patients with HNSCC (6).