The vascular endothelial growth factors and receptors family: Up to now the only target for anti-angiogenesis therapy.

Angiogenesis is a complex biological phenomenon essential for a correct embryonic development and for post-natal growth. In adult life, it is a tightly regulated process but in several pathological conditions, angiogenesis results abnormal with either excessive or insufficient proliferation of blood vessels. The pro-angiogenic members of VEGF family, VEGF-A, VEGF-B and placental growth factor (PlGF), and the related receptors, VEGFR-1 and VEGFR-2, have a central and decisive role in pathological angiogenesis. Indeed, they are the targets for anti-angiogenic drugs currently approved: bevacizumab and ranibizumab, that specifically inhibit VEGF-A; aflibercept, that is able to prevent the activity of VEGF-A, VEGF-B and PlGF; several multirtarget tyrosine kinase inhibitors that are able to prevent VEGFR-1 and/or VEGFR-2 signaling. The anti-angiogenesis therapy has represented one of the most active fields of drug discovery of last decade and promises to be further expanded due the wide number of diseases for which it may by applied.