Vascular endothelial growth factor C (VEGF-C) is a member of the VEGF/platelet-derived growth factor (PDGF) family of proteins. VEGF-C is a potent angiogenic factor and promotes lymphangiogenesis, endothelial cell growth and survival, and can affect blood vessel permeability. VEGF-C is expressed in a range of tissues, but is not expressed in peripheral blood lymphocytes. VEGF-C forms a non-covalent, cell surface-associated, disulfide-linked homodimer that can bind and activate VEGF receptors 2 (VEGFR-2 [Flk1]) and 3 (VEGFR-3 [Flt4]). Interaction with VEGFR-2 results in physiological and intratumoral neoangiogenesis and vessel sprouting (Cao et al.; Tammela et al.), whereas interaction with VEGFR-3 is critical for lymphangiogenesis (Karkkainen et al.; Laakkonen et al.; Mäkinen et al.). Overexpression of VEGF-C in tumor cells has been shown to result in enhanced lymph flow and increased metastasis to regional lymph nodes (Hoshida et al.; Mandriota et al.; Padera et al.; Skobe et al.).