NCIt definition : There are three signaling VEGF receptors. The VEGF family members PIGF and VEGF-B
with exclusive binding capacities to the VEGFR-1 can influence monocyte activation
and differentiation. The VEGFR-2 and VEGFR-3 binding VEGF homologues, VEGF-C and VEGF-D,
are mitogens for both vascular and lymphatic endothelial cells. The orf virus encoded
VEGF-E homologue binds and activates only the VEGFR-2 and thus may be the prototype
of a vascular endothelial cell-specific growth factor. Further specific activities
of VEGF and its homologues result from receptor-specific signaling and differential
expression of ligands or receptors. A naturally occurring soluble form of the VEGFR-1
suggests a regulatory role for this receptor.;