Gefitinib (ZD1839, Iressa) [36] and erlotinib (OSI-774, Tarceva) [37] belong to the first generation of TKIs and are selective EGFR–TKIs that were approved on May 2003 and November 2004 for the treatment of NSCLC patients, respectively (Table 2) [30,38]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.