EGFR and head and neck squamous cell carcinoma: In recent years, inhibition of epidermal growth factor receptor (EGFR) signaling by use of anti-EGFR antibodies (e.g., cetuximab and panitumumab) or EGFR tyrosine kinase inhibitors (e.g., gefitinib and erlotinib) has emerged as a new treatment strategy; however, so far cetuximab is the only EGFR-targeted drug approved for the treatment of HNSCC.