EGFR and cancer: In the past twenty years, with the discovery and better understanding of mutations in the epithelial growth factor receptor (EGFR) as a cancer-driving event and the use of tyrosine kinase inhibitors (TKIs), patients with lung cancer harboring EGFR-sensitizing mutation have benefited from prolonged progression-free survival (PFS) compared with patients who received conventional platinum-based chemotherapy only [4].