 Patients with disease progression on or after first line therapy may be candidates for second line chemotherapy with either docetaxel or pemetrexed, which results in a modest improvement in survival. More recently, 2 EGFR tyrosine kinase inhibitors TKIs, gefitinib and erlotinib, have been approved for second and third line therapy in advanced NSCLC 13,14. The effect on overall survival in genotypically uncharacterized patients was observed with erlotinib BR21 trial, but not with gefitinib ISEL trial, contributing to the withdrawal of gefitinib from the United States, and the approval of erlotinib as second and third line therapy in NSCLC irrespective of tumor genotype 15. 