The majority of patients exhibiting common EGFR mutations are typically nonsmokers or former light smokers and have been diagnosed with adenocarcinoma histology [28], and are also of younger age and female sex [29], although some studies show no statistically significant association between sex, histologic subtype and racial differences and EGFR mutation status [30,31], or with age, performance status or smoking status [31]. Here, EGFR is linked to adenocarcinoma.