After adjusting the effects of pack-years smoked, green tea consumption, exposure to fumes of cooking, and family history of lung cancer, those subjects with both lower miR-29b expression and higher DNMT3B mRNA expression, those with both higher miR-29b expression and higher DNMT3B mRNA expression, and those with both lower miR-29b expression and lower DNMT3B mRNA expression had a 2.59-fold (95% CI 1.56–4.31), 1.62-fold (95% CI 0.97–2.72), and 1.75-fold (95% CI 1.06–2.90) increased risk of lung cancer compared to the reference group, respectively. The gene discussed is DNMT3B; the disease is lung cancer.