Little is known about the relationship between these oncogenes of the EGFR family and the recently described oncogenes FGFR4 and fusion gene EML4-ALK. Recent data suggests molecularly defined subgroups of non-small cell lung cancer (NSCLC) exist and can be used to predict for sensitivity to targeted agents (erlotinib or gefitinib) or cytotoxic chemotherapy (pemetrexate, gemcitabine, platinum agents). The findings that estrogen receptors are present in lung tumours and that estrogen can stimulate growth and proliferation of lung cancers in vitro and in vivo are provocative. Further studies to evaluate the role of estrogens and other sex hormones in lung cancer are warranted.