Both first and second generation EGFR-targeted TKIs (gefitinib and erlotinib) targeting those activating mutants have been demonstrated to have a remarkable clinical response in the treatment of EGFR-mutated NSCLC (Lynch et al., 2004; Paez et al., 2004; Jackman et al., 2009; Rosell et al., 2009; Sequist et al., 2010). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.