Although the most important mechanism of action is the inhibitory effect over VEGF, thus inhibiting proliferation of endothelial cells, endothelial growth and cause regression of existing vessels increasing endothelial cell death; other mechanisms have been proposed, including prevention of VEGF-induced vessel permeability, lowering blood inflow through A-V shunts, decrease in cardiac output in patients with severe hepatic vascular malformations and improvement of anemia by reducing epistaxis and gastrointestinal bleeding 21-.23 This evidence concerns the gene VEGFA and anemia.