YB-1/p18 is largely absent in plasma samples of healthy blood donors, patients with inflammatory and renal diseases, but found in metastatic cancerous diseases and hepatocellular carcinoma. A. Plasma samples from 33 healthy blood donors were analyzed for the presence of YB-1/p18. In none of these samples YB-1/p18 was present (representative blots are shown). Positive control plasma from cancer patient is indicated by "+". The relative optical density (OD) assessed by densiometry is given. Positivity was considered, if relative OD > 0.45. In each blot, one positive control sample obtained from a patient with metastasized small cell lung cancer was run in parallel, that was strongly YB-1/p18 positive. The YB-1/p18 signals were quantified by densiometry (NIH imager) and compared to the positive control signal which was assigned the optical density of "1.0". The relative optical density of the sample signals was calculated accordingly. B. Analysis of 60 plasma samples collected from patients with various underlying, non-cancerous diseases was performed for the presence of YB-1/p18. Corresponding C-reactive protein (CRP) and creatinine levels are provided for each patient. Representative blots are shown. C. Immunoblotting with biotinylated monoclonal anti-YB-1 antibody was performed for YB-1/p18 in 25 individual patients with primary hepatocellular carcinoma (HCC). Representative blots are shown. D. Immunoblotting with biotinylated monoclonal anti-YB-1 antibody was performed for YB-1/p18 in 20 individual patients with various advanced cancer diseases and liver metastases. Representative blots are shown.