The primary objective of this study is to develop a blood-based gene expression signature, known as the ONC-LN-04 Lung Test, to be used in the detection of lung cancer in patients who underwent radiologic screening for lung cancer and had lung nodules detected. We intend to enroll volunteers who are being evaluated by a Medical University of South Carolina (MUSC) pulmonologist as part of their standard medical care. Participants will be current or former smokers, who have either (a) radiologic evidence of lung nodules, or (b) a confirmed diagnosis of non-small cell lung cancer (NSCLC) and has not undergone surgical excision, chemotherapy or radiation therapy for this malignancy. A single blood sample will be obtained from willing participants, then stored and analyzed for measurement of gene expression and development of the ONC-LN-04 test. Active participation in this study will be over once a blood sample is obtained; however, we may need access to participants' medical records post-enrollment and sample collection in order to monitor medical outcomes. Review of participants' medical records will occur until up to approximately 3,500 subjects have been enrolled and have provided clinical information and a blood sample.