EGFR exon 20 insertion mutations are the third most common type of EGFR mutation in NSCLC [22], as observed in our study, and are estimated to account for 0.1% to 4.0% of all NSCLC cases [23] (0.2% at IPO Porto, with six out of 3389 cases) and 4% to 12% of all EGFR mutations [23] (5.5% at IPO Porto, with six out of 110 cases). This evidence concerns the gene EGFR and non-small cell lung carcinoma.