Delineating VEGF-C activation is not only important in order to understand the development of the lymphatic system, but also to understand tumor angiogenesis, because mature VEGF-C is also able to activate the VEGFR-2 signaling pathway and because some tumors might escape antiangiogenic therapy by employing VEGF-C instead of VEGF-A32. This evidence concerns the gene KDR and neoplasm.