Dr. Alitalo discovered the endothelial growth factor VEGF-C and its receptor VEGFR-3, contributed to the characterization of VEGF-D, and to the discovery of VEGF-B, a coronary vessel growth factor. He discovered the first endothelial receptor for angiopoietins, and the developmental and disease-associated roles of these vascular growth factors. He found that the Schlemm’s canal is a lymphatic-like vessel, that VEGFR-3 mutations cause Milroy’s disease and established VEGF-C therapy for lymphedema that is currently in phase 2 clinical trial. He showed that VEGFR-3 is essential for the development of the cardiovascular system. His studies led to a phase 2 clinical trial using antibodies against VEGF-C and VEGF in patients with the wet form of age-associated macular degeneration and diabetic macular edema. His most recent discovery was the VEGF-C-driven meningeal lymphatic vascular system that drains brain interstitial fluid and macromolecules and enables brain immunosurveillance.