Overall study design Eligible patients will have a histologic or cytologic diagnosis of NSCLC; advanced-stage disease who are appropriate candidates for therapy with nivolumab, pembrolizumab or atezolizumab, and age greater than 18 years. Prior surgery, chemotherapy and/or radiotherapy are allowed. Inclusion and exclusion criteria are outlined in the appropriate section. All inclusion and exclusion criteria will be assessed within 6 weeks prior to the first dose of nivolumab, pembrolizumab or atezolizumab. Baseline radiographic studies should be performed within 30 days of screening. This clinical study will require central IRB approval. Informed consent will be obtained from each patient prior to screening and enrolling in the study.