Figure 1: Schematic presentation of possible interactions between surface-bound proteins and cell-membrane receptors. Cell-surface receptors include integrin, which interacts with adhesive proteins such as Fibronectin (FN), VEGF receptor (VEGFR-1 and VEGFR-2), and Tie-1 and Tie-2, all of which are specific to Endothelial Cells (ECs) and their progenitor cells (EPCs). Ligands are FN, VEGF, and corresponding anti-receptor antibodies