Lung cancer is a deadly disease affecting millions of people worldwide.Chest computed tomography(CT)is a powerful tool for diagnosing early-stage lung cancer but is prone to false positives.As a result,many patients with benign pulmonary nodules undergo unnecessary and invasive procedures such as biopsy and surgery.We report here the development and validation of a blood-based multiplexed protein test that stratifies benign nodules from malignant ones.1 Key development strategies for the test are discussed.The test is now commercialized in US with the aim of helping physicians rescue patients with benign pulmonary nodules from invasive procedures.