Figure 4.

VEGF signaling pathways. Binding specificity of various vascular endothelial growth factor (VEGF) family members and their receptors. The VEGF family consists of seven ligands derived from distinct genes (VEGF-A, -B, -C, -D, and -E, placenta growth factor [PIGF] -1 and -2). VEGF family members have specific binding affinities to VEGF receptor (VEGFR) -1, VEGFR-2 and BEGFR-3 tyrosine kinase receptors as shown. In addition, neuropilin (NRP)-1 and NRP-2 are co-receptors for specific isoforms of VEGF family members and increase binding affinity of these ligands to their respective receptors. Used with permission from: Hicklin DJ, Ellis LM. Role of the vascular endothelial growth factor pathway in tumor growth and angiogenesis. J Clin Oncol 2005; 23: 1011–27.