Lighthouse-Lung Cancer Screening Study Sponsor and Protocol Number: Hoffman La Roche (GO44296) Specialty: Internal Medicine/Oncology Type: Biospecimen Inclusion:Age 50 - 80Current or former smoker (must have quit 15 years ago or less)Undergoing a LDCT in the next 90 days Exclusion:Personal history of cancerPneumonia in the last 12 weeksHome oxygen use (CPAP okay)On any immunosuppressant drugsHistory of organ transplant