Inclusion Criteria:  Age from 18 to 75 years old Advanced non-small cell lung cancer (stage IIIB-IV), pathological types limited to squamous cell carcinoma or adenocarcinoma, driver gene mutations (EGFR/ALK/ROS1) were negative General condition: ECOG score 0 or 1 First-line monotherapy or combination immunotherapy The long-term benefit of immunotherapy was defined as PFS=12months Tumor tissue samples can be obtained at the time of enrollment, and at least 5 ~ 10 sections can be generated, and the pathological report indicates that the overall tumor content is not less than 10%. At least one measurable lesion (except patients with CR after first-line treatment) can be evaluated according to RECIST1.1 standard. Have self-awareness, be able to understand the research scheme and voluntarily participate in the study, and can sign the informed consent form Have good compliance, be able to cooperate with the collection of specimens from each node and provide corresponding clinical information.  Exclusion Criteria:  Serious primary diseases of the heart, liver and kidney Other malignant tumors within 3 years prior to diagnosis of NSCLC Women in pregnancy and lactation The active stage of human immunodeficiency virus (HIV) infection Patients with active systemic infection, pneumonia, tuberculosis, pericarditis Patients who cannot understand the content of the experiment and cannot cooperate and refuse to sign informed consent.