In this white paper, Sang Hoon Lee of Hanhwa Biologics discusses angiogenesis and tumour growth in vivo. Vascular endothelial growth factor (VEGF) signaling pathway have always been the method of choice for cancer treatment. However, VEGF inhibitors alone can promote tumor invasion and metastasis by increasing intratumoral hypoxia as shown in some preclinical models. Emerging reports have shown that Delta-like-ligand 4 (Dll4) …