Lung cancer is the leading cause of cancer deaths,and the key to reducing mortality in lung cancer patients is early diagnosis and treatment.Currently,peripheral blood DNA methylation is a novel in vitro molecular marker for tumors.Meanwhile artificial intelligence diagnostic system can further improve the diagnostic ability.The purpose of this study is to apply the overall DNA methylation level (i.e.,methylation profile) and the altered methylation degree of specific genes as tumor diagnostic indexes,and combined with the artificial intelligence imaging technology for the early and accurate diagnosis of lung cancer,to achieve the early detection,diagnosis,and treatment of lung cancer,and to effectively reduce the mortality rate of lung cancer.

Inclusion Criteria:

• (1) Patients with pulmonary nodules diagnosed by imaging;
• (2) No contraindications to blood collection;
• (3) Voluntary completed DNA methylation testing;
• (4) Signed informed consent and performed all the study mandated procedures.

Exclusion Criteria:

• (1) Pregnant or lactating(6 months) women;
• (2) History of malignancy or known malignancy or precancerous lesions or known tuberculosis within 3 years;
• (3) Autoimmune system disorders;
• (4) Undergoing any diagnostic puncture therapy, such as percutaneous lung biopsy, transbronchial, pre-enrollment biopsy, or surgical procedures (within 6 months); (5) Recipients of organ transplants or prior non-autologous (allogeneic) bone marrow transplants or stem cell transplants; (6) Received antibiotic therapy within 14 days or applied a drug that elevates white blood cells within 45 days prior to the blood draw.

Patients with single pulmonary nodule found by CT scan.