EGFR and lung adenocarcinoma: Lung cancerconstitutes the leading cause of cancer-related deathsworldwide (18%) and non-small cell lung cancer (NSCLC) representsthe majority of lung cancer cases (85%).6,7 Oncogenic mutationsof the EGFR kinase domain are the most common activating driver mutationsin lung adenocarcinomas.8 After in-framedeletions of exon 19 (ex19del) and single point mutations at codon858 in exon 21 (L858R), insertion mutations within exon 20 (ex20ins)are the third most prevalent mutations of EGFR (4–10%).4,9−11