Few studies so far have focused specifically on lung cancer in women, despite increasing evidence of differences in lung cancer features between women and men. A striking example is the higher rate among women of nonsmokers who develop lung cancer. A recent study of women with lung adenocarcinoma, a type of non-squamous non-small cell lung cancer (NSCLC), found that those who had never smoked were much more likely to have mutations in the EGFR gene and/or abnormally high levels of estrogen receptors, while smokers were more likely to have mutations in the KRAS gene. Based on these findings, a new phase II clinical trial will explore the effectiveness of treating postmenopausal, nonsmoking women who have advanced non-squamous lung cancer with EGFR inhibitors and anti-estrogen drugs.