Cancer and cardiovascular diseases are the leading causes of morbidity and mortality in the developed countries. Current cardiovascular and cancer therapies are often insufficient, unsuccessful or not suitable for all patients, thus novel therapies are urgently needed. Inhibition of angiogenesis is already used in the clinics, but with limited success. On the other hand, stimulation of the growth of blood vessels, angiogenesis, and of arteriogenesis has been unsuccessfully tried for the treatment of tissue ischemia in humans. The elucidation of disease-related functions of endothelial growth factors and their signal transduction in cancer and cardiovascular disease should help in development of improved therapy for these diseases. Possible new therapy requires on solid knowledge of the biology of vascular endothelial growth factors, angiopoietins, angiogenesis and lymphangiogenesis.