PECAM1 and neoplasm: The table also includes negative surface markers, such as Receptor-Type Tyrosine-Protein Phosphatase C (CD45), the marker of hematopoietic cells, Cell Surface Glycoprotein MUC18 (CD146), the marker of endothelial cells in the vascular system, Hematopoietic Progenitor Cell Antigen CD34 (CD34), the marker for identifying stem cells, Platelet Endothelial Cell Adhesion Molecule (CD31), the marker for identifying leukocyte subsets, and Epithelial Cell Adhesion Molecule (CD326), the marker for identifying epithelial cells and epithelia-derived neoplasms.