EGFR and cancer: The epidermal growth factor receptor (EGFR) is known to play a role in the development and progression of cancer, and small molecular EGFR tyrosine kinase inhibitors (EGFR-TKI), including gefitinib (Iressa®; Astra Zeneca, Macclesfield, UK) and erlotinib (Tarceva®; OSI Pharmaceuticals Inc., Melville, NY, USA), are available (Arteaga, 2002; Meert et al, 2002; Schlessinger, 2002; Herbst and Bunn, 2003).