CD31/PECAM-1, or platelet endothelial cell adhesion molecule 1, is a 130-kDa glycoprotein expressed on vascular and hematopoietic cells. Depending on the cell type, CD31/PECAM-1 expression can be largely localized to cell junctions, playing a role in cell adhesion. Aside from its role in cellular adhesion, CD31/PECAM-1 is also a large player in a variety of signaling pathways, such as angiogenesis, cell migration, leukocyte transmigration and more. Specifically, the association and indication of angiogenesis in breast cancer is of interest, given that extensive research shows an
