Tumour growth, spreading and metastasis require the development of a local vasculature. There have been great advances in the understanding of how this new vasculature arises, particularly in our increased knowledge of the process of angiogenesis, Although, a vast number of pro-angiogenic and anti-angiogenic mediators have been identified, one of the key signalling processes in the development of the tumour vasculature is the hypoxia-induced stimulation of vascular endothelial cell growth factors (VEGFs) production. Anti-VEGF therapy therefore not only provides a new paradigm for limiting tumour growth via targeting angiogenesis, but also provides prototypic agents to test the hypothesis that by controlling the development of the tumour vasculature we are able to limit, and potentially stop, tumour growth and spreading.