EGFR and adenocarcinoma: Interestingly, although EGFR mutations are more commonly associated with specific clinicopathological features such as female gender, Asian ethnicity (where they can be found in up to 30% of advanced NSCLCs as opposed to 15% for the western population), non-smoking history, and adenocarcinoma histology [23], it is not possible to rule out the possibility of an EGFR mutation solely on the basis of the aforementioned characteristics.