The lung is usually not considered a target organ for sex hormones; however, specific estrogen and progesterone receptors are distributed in normal lung tissue and some lung cancers.7-10 Animal experiments have demonstrated that sex hormones directly alter fetal lung differentiation11 and have affected the incidence of pulmonary neoplasms in adulthood.12 In addition, estrogens have been shown to influence the development of carcinoma in other organs such as pancreas,13 stomach14,15 and colon.15 Epidemiologic data on the role of female hormones in lung cancer etiology have been mixed. The gene discussed is PGR; the disease is lung cancer.