Although the frequencies of CT and TT homozygotes among lung adenocarcinoma patients were lower than those in the control group (50.7% vs. 51.8% in CT, 20.6% vs. 23.0% in TT, respectively), no significant association between the TGF-β1 C509T polymorphism and the risk of lung cancer was found. The gene discussed is TGFB1; the disease is lung cancer.