Tumor angiogenesis is the process by which new blood vessels form from existing ones to supply nutrients and oxygen to a growing tumor. This process is crucial for tumor growth and survival, as tumors require a blood supply to expand beyond a certain size. The formation of these blood vessels is driven by various signaling molecules, including vascular endothelial growth factor (VEGF). By promoting angiogenesis, tumors can enhance their growth and spread, making it a significant target for cancer therapies aimed at inhibiting this process.