EGFR mutations are present in 10% to 15% of NSCLC, occurring in higher frequency in lung adenocarcinoma, patients with light or never smoking history, women, and those of East Asian descent.1, 2, 3EGFR mutations are heterogeneous and variable in frequency, with the in-frame deletion of exon 19 (Ex19del) and the L858R point mutation comprising approximately 80% to 85% of all EGFR mutations.1 Here, EGFR is linked to lung adenocarcinoma.