In patients with pulmonary nodules under 45 years old, no statistical association was found between ACE1 rs4646994 and lung cancer risk, while in older patients (>45), the risk of lung cancer was significantly increased in patients with the DD genotype (DD vs. ID + II: OR = 3.423, 95% CI, 1.284–9.126, p = 0.014). This evidence concerns the gene ACE and lung cancer.