This study plan to enroll 852 patients with pulmonary nodules smaller than 3 cm in diameter, whose DNA and RNA will be extracted from mature red blood cells isolated from peripheral blood. The DNA 5-methylcytosine(5-mC) and RNA 2'-O-methylation information will be acquired by NGS and Nm Judge Universally sequencing (NJU-Seq), which will be used to establish models to distinguish patients with benign and malignant nodule in the training group and further evaluated in the validation group. The pathological results will be acquired after surgery or biopsy as standard in the study.

This is a prospective, multi-center, observational, cohort study and seeks to enroll 852 participants with pulmonary nodules smaller than 3 cm in diameter from 4 hospitals in China.

Each participant pulmonary nodule is ≤30mm as assessed by CT scanning, nodule is suspected to be malignant, and plan to use biopsy or surgery for diagnosis or treatment within 60 days.Their blood samples, CT scan data, and clinical data will be collected at each visit and tissues will be collected when participants who receive pneumonectomy or percutaneous lung biopsy.

Each subject will analysis DNA and RNA methylation in nucleic acids extracted from mature red blood cells isolated from peripheral blood by next-generation sequencing (NGS) . A proprietary algorithm will be used to identify the modification sites and pattern for differentiating the benign and malignant pulmonary nodules. Sensitivity and specificity of the different methylation panels will be to evaluated.

Inclusion Criteria:

1. Pulmonary nodule is ≤3cm;
2. Subjects suspected of lung cancer;
3. Diagnosis or treatment by biopsy or surgery within 60 days;
4. Signed informed consent.

Exclusion Criteria:

1. History of malignant tumors;
2. Received anti-tumor therapy;
3. Can't collect the histopathological results or the pathological results are metastatic cancer;
4. Can't obtain detection information of red blood cells;
5. Pregnancy or lactating female；
6. Other situations not suitable for the study.

1. The pulmonary nodule is ≤30mm as assessed by imaging; nodules were suspected to be malignant,
2. Plan to use biopsy or surgery for diagnosis or treatment within 60 days.