However, while first generation EGFR-TKIs gefitinib (Iressa, ZD1839; AstraZeneca) and erlotinib (Tarceva, OSI-774; Genentech) have worked well in a subset of patients carrying mutations in the EGFR kinase domain in NSCLC [7], a significant proportion developed primary and secondary drug resistance during treatment [8]. This evidence concerns the gene EGFR and non-small cell lung carcinoma.