For a tumour to grow, it must develop blood vessels that supply nutrients and oxygen. Preventing tumor vascularization is therefore an interesting anti-tumor therapy that has been explored over the last ten years. But how to be truly effective? By identifying two cytokines, key factors in the recruitment of blood cells essential to the formation of new blood vessels, and above all by deciphering how these factors interact simultaneously with blood vessels, researchers are now highlighting an additional way of controlling tumor progression.