EGFR and lung adenocarcinoma: Our recent study (2012) [17] also indicated that EGFR mutation shift deriving from chemotherpy may be related to the heterogeneity of intratumoral EGFR mutation and to different chemosensitivity levels of mutant and wild-type cells, In contrast, Yatabe et al (2011) [18] reported that EGFR heterogeneity occurred extremely rarely in lung adenocarcinoma.