fig3

Figure 3. The classification of EPC paracrine factors. TNF-α: Tumor necrosis factor-alpha; TNFR: tumor necrosis factor receptor; VEGF: vascular endothelial growth factor; NRP: neuropilin; PDGF: platelet-derived growth factor; BMP: bone morphogenetic protein; TGF-β: transforming growth factor-beta; ICAM: intercellular adhesion molecule; EPCs: Endothelial progenitor cells.