Analysis of Drug Resistance in Immune Checkpoint Inhibitors of Non-small Cell Lung Cancer

Inclusion Criteria: * Be able to provide informed consent, and understand and agree to follow the research requirements; * Advanced non-small cell lung cancer; * Patients receiving immune checkpoint inhibitor treatment represented by anti-PD-1/PD-L1 monoclonal antibody; * The patient must be able to provide fresh tumor tissue before- and after- ICIs (50mg of tumor tissue sample/ 2 needles of 18G thick needle puncture) or tumor tissue archived within one year (FFPE tissue block or about 15 pieces \[10- 15 sheets\] Freshly cut, unstained FFPE slides) and pathology reports (except for advanced non-small cell lung cancer other than neuroendocrine cancer); provide matched 10mL peripheral whole blood samples at the same time; * ECOG physical fitness status ≤1; * The patient must have at least one measurable lesion (assessed according to RECIST v1.1); * Life expectancy ≥ 12 weeks; * The patient must have adequate organ function, and must be reached absolute neutrophil count (ANC) ≥1.5x10\^9/L, platelets ≥100x10\^9/L, hemoglobin ≥90g/L, international normalized ratio (INR) or prothrombin time ≤ 1.5x ULN , activated partial thromboplastin time (aPTT)≤1.5x ULN, serum total bilirubin≤1.5x ULN (Patients with Gilbert syndrome can be enrolled if total bilirubin\<3x ULN), Aspartate aminotransferase (AST) and alanine aminotransferase (ALT)≤2.5x ULN(Patient with liver metastases, this standard is AST and ALT≤5x ULN) within 7 days before treatment; Exclusion Criteria: * Patients with other tumors. Except for basal cell carcinoma of the skin, superficial bladder cancer, squamous cell carcinoma of the skin or cervical cancer in situ, subjects who have received potential radical treatment and have not relapsed within 5 years before the start of treatment can be included in the study; * Have received any approved systemic anti-tumor immunotherapy before starting the research treatment; * A history of interstitial lung disease, non-infectious pneumonia or uncontrolled systemic diseases, including diabetes, hypertension, pulmonary fibrosis, acute lung disease, etc.; * Severe chronic or active infections that require systemic antibacterial, antifungal or antiviral therapy, including tuberculosis infection; * Known human immunodeficiency virus infection; previous allogeneic stem cell transplantation or organ transplantation; * The investigator judged that the patient's compliance during the study period was insufficient