EGFR and lung adenocarcinoma: EGFR mutations includes three types (point mutation, multinucleotide in-frame deletion,and in-frame insertion) which have been documented in exon 18 through 21, highlighting that deletion mutation in exon 19 (45%) and point mutation in exon 21 (40–45%) are two most common mutations, accounting for about 90% EGFR mutations in lung adenocarcinoma (12).