First-generation EGFR TKIs including erlotinib and gefitinib were first approved the U.S. Food and Drug Administration (FDA) in 2013 for first line use in metastatic EGFR ex19dels or L858R mutant NSCLC in 2013 after multiple studies demonstrated improved clinical outcomes compared to platinum-based chemotherapy (17, 18). Here, EGFR is linked to non-small cell lung carcinoma.