Rare EGFR mutations have been reported to be present at a rate of 12% in adenocarcinoma patients, with G719X having a prevalence of 13.78%, S768I/V having a prevalence of 6.39%, exon 20 insertions having a prevalence of 16.85%, and L861X having a prevalence of 9.88% [23]. The gene discussed is EGFR; the disease is adenocarcinoma.