Peptide Signature of Breast Cancer Cells (IMAGE) Houston Methodist Caption Small clusters of young tumor cells around blood vessels produce signature peptides (small pink lines). Some of these peptides move into the bloodstream -- where they can be detected by a serum-based tool currently in development. Credit Tony Hu lab Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.