We assessed the top five over-expressed and under-expressed proteins in malignant vs non-malignant states for their potential as biomarker candidates and found that two, NPC2 and MDK - both of which are predicted to have a signal peptide and extracellular localization (Supplementary Table 1) – have been found to be over-expressed in mouse LUAD plasma and NSCLC patient serum, respectively, confirming their secretion (64, 65). The gene discussed is MDK; the disease is non-small cell lung carcinoma.