Several EGFR-TKIs have been approved for the first-line treatment of patients with metastatic disease and EGFR-activating mutations (exon 19 deletion, L858R) [8], including osimertinib (the preferred option in most guidelines), gefitinib, erlotinib, afatinib and dacomitinib. The gene discussed is EGFR; the disease is metastatic neoplasm.