**6. The development of anti-angiogenic therapies**

Given the key role VEGF is proposed to play in tumour angiogenesis, it is unsurprising that it has become a major drug target. Various drugs designed to inhibit VEGF signalling have been developed, including VEGF neutralising antibodies (e.g. bevacizumab), novel fusion proteins which bind pro-angiogenic growth factors (e.g. aflibercept) and VEGF receptor tyrosine kinase inhibitors (e.g. sunitinib) [5, 21]. Such agents have shown promise in the treatment of several malignancies, including mCRC, metastatic renal cell carcinoma (mRCC), metastatic lung cancer, hepatocellular carcinoma (HCC) and pancreatic neuroendocrine tumours (PNET) [22].
