Therapeutic ResistAnce and Clonal Evolution Assessed With Liquid Biopsy in ICIs Treated NSCLC Patients

This observational study collects blood samples (liquid biopsies) from patients with advanced non-small cell lung cancer (NSCLC) who are receiving immunotherapy as their first treatment. The goal is to understand how the cancer evolves and why some patients stop responding to immunotherapy. **You may be eligible if...** - You have been newly diagnosed with Stage IIIB or IV lung adenocarcinoma or squamous cell carcinoma - You are receiving immunotherapy (checkpoint inhibitors) as your first line of treatment - Your tumor does not have an EGFR mutation - You are in reasonably good health (ECOG 0-2) with an expected survival of more than 6 months - You are willing to have blood samples collected at various timepoints **You may NOT be eligible if...** - You have another active primary cancer - You have symptomatic brain metastases or cognitive disorders - Your blood or tissue samples fail quality control standards Talk to your doctor to see if this trial is right for you.