Recently, we evaluated the performance of 190 candidate protein biomarkers to discriminate between patients with benign or malignant lung nodules.  The candidate markers came from the substantial literature on cancer-associated proteins as well as from mass spectrometry studies, conducted in-house to identify proteins up-regulated either on the surface of tumors or in the secretome of tumors, as compared to adjacent normal lung tissue. Plasma samples were obtained retrospectively for analysis from those with either benign or malignant nodules.  A 13 protein panel was identified with a high negative predictive value, able to remove approximately half of those with benign nodules from further consideration.  The test has been commercialized, using MRM mass spectrometry, by Integrated Diagnostics.