Comparison of ligand/VEGFR-2 D23 complex structures. Ribbon diagram of the superposition of VEGF-A (red), VEGF-C (green, pdb 2X1X), and VEGF-E (blue) complexes with VEGFR-2 D23 (gray). Na and Nc amino termini of VEGF-A and -C, respectively, the VEGF loops L1-L3, and the aminoterminal helix (αN) are labeled where applicable.