Notably, 15–30% of NSCLC patients have tumors harboring activating mutations in the epidermal growth factor receptor (EGFR) that have been associated with a response to EGFR tyrosine kinase inhibitors (TKIs)1, 3, and the most frequently detected alterations were small deletions in exon 19 (35–45%) that eliminate amino acids 747–750 (Leu-Arg-Glu-Ala), located around the active site of the kinase4. This evidence concerns the gene EGFR and non-small cell lung carcinoma.