VEGF-C is essential for embryonic lymphatic vascular development whereas VEGF-D has a dispensable modifier role in this process. Nevertheless, both growth factors potently stimulate lymphangiogenesis in adults. VEGFR-3 is required for the remodeling of the primary blood vascular plexus in midgestation mouse embryos, apparently in a VEGF-C/VEGF-D independent manner.7 Later in embryogenesis, VEGFR-3 becomes restricted to lymphatic vessels and is critical for embryonic lymphangiogenesis and postnatal lymphatic vessel survival. At least in adult lymphangiogenesis, VEGFR-3 can cooperate with the major angiogenic receptor, VEGFR-2. ? indicates possible additional ligand or interaction.
