EGFR and neoplasm: Gefitinib (Iressa, ZD1839), an orally available low molecular weight quinazoline derivative, is an EGFR tyrosine kinase inhibitor (EGFR-TKI) that selectively inhibits the MEK1/2-ERK1/2 cascade by blocking EGFR autophosphorylation and inducing apoptosis of EGF-stimulated tumor cells [36].