Lung cancer is the leading cause of mortality in the world. Previous study has shown that about 88% lung cancer cases belong to non-small cell lung cancer (NSCLC) in Taiwan (1). Approximately 50~90% of NSCLC patients had expression (or described as overexpression) of EGFR in cancer (2,3). Although targeting the EGFR kinase domain using the inhibitors gefitinib (Iressa) and erlotinib (Tarceva) has no effect against solid tumors, it achieves impressive response in subgroup of NSCLC especially in Asian ethnic background, female sex, the absence of a history of smoking, and a tumor with histologic feature of adenocarcinoma (3,4,5). Molecular studies of highly responsive cases revealed high percentage of somatic mutation within the tyrosine kinase, ATP-binding domain of the EGFR gene (6). One possible explanation for this phenomenon is that the cancer cells are "addicted" to signaling via the mutant EGFRs and die when the mutant oncoprotein is inactivated (7). However, specific mechanisms underlying epidermal growth factor tyrosine kinase inhibitor (EGFR-TKI) induced cell death have not been well delineated (7).