Clinical profiles of females, never smokers, adenocarcinoma histology, and Asian ethnicity have all been recognized as favorable subgroups that respond to gefitinib.[21–23] Higher EGFR mutation rates are also noted in these subgroups and are also related to a better response to EGFR-TKIs.[7, 24] Nevertheless, the potential gender effect was not demonstrated in the INTACT-2 study.[5] Moreover, in the study of Takeda et al.,[16] the benefit of adding gefitinib to platinum-doublet chemotherapy was only shown for smokers, while never-smokers showed no significant benefit. Here, EGFR is linked to adenocarcinoma.