VEGF R2 is a member of the class III subfamily of receptor tyrosine kinases (RTKs) that also includes VEGF R1 (Flt-1) and VEGF R3 (Flt-4). All three receptors contain seven Ig-like repeats within their extracellular domains and kinase insert domains in their intracellular regions. The expression patterns of VEGF R1, VEGF R2, and VEGF R3 are almost exclusively restricted to endothelial cells. These receptors play essential roles in angiogenesis. VEGF R2 binds VEGF-A (VEGF121, VEGF165, VEGF189 and VEGF206 splice variants), VEGF-C and VEGF-D. The full-length cDNA for VEGF R2 encodes a 1356 amino acid (aa) precursor protein with a 19 aa signal peptide. The mature protein is composed of a 745 aa extracellular domain, a 25 aa transmembrane domain and a 567 aa cytoplasmic domain.