EGFR and head and neck squamous cell carcinoma: These pathways, which include RAS–MAPK signalling, have been extensively studied in HNSCC, and seem to have a critical role in the survival and proliferation of cancer cells (Kalyankrishna and Grandis, 2006) and EGFR is overexpressed in more than 50% of HSCC specimens (Frank et al, 1993).