# What is angiogenesis? Angiogenesis is the process of forming new blood vessels from existing ones. It occurs during development, tissue repair, and in certain diseases such as cancer. In normal development and tissue repair, angiogenesis helps to deliver oxygen and nutrients to cells and tissues. However, in cancer, angiogenesis is abnormal because it provides tumours with a blood supply that they shouldn't normally have access to. Angiogenesis brings oxygen and nutrients to the tumor cells, allowing the tumor to continue growing and spreading. Angiogenesis is regulated by a balance of pro-angiogenic (activators) and anti-angiogenic factors (inhibitors). Pro-angiogenic factors activate the growth of new blood vessels, while anti-angiogenic factors inhibit their growth. Cancer has the ability to shift these factors in favour of angiogenesis, leading to the formation of new blood vessels that support tumor growth. Understanding angiogenesis is important because it has potential to be used as a tool against cancer. For example, drugs, supplements and foods that block angiogenesis have shown benefit in cancer treatment, and research is ongoing to find new ways to target angiogenesis as a way to fight cancer's growth. # Why is angiogenesis important to cancer treatment? Inhibiting angiogenesis has been a target of cancer research, as it may be possible to slow or stop the growth and spread of cancer by blocking the formation of new blood vessels. Some standard care cancer treatments, such as certain types of [chemotherapy](../3.%20Treatments/3.6%20%20Standard%20care/Chemotherapy.md), work by inhibiting angiogenesis. But there are many other ways of inhibiting angiogenesis, such as foods, botanical supplements, and off-label drugs. One of the people who got me started on understanding angiogenesis inhibitors is [Dr. William Li](../5.%20Resources/People/Dr.%20William%20Li.md), who has a great book and Ted talk on the subject.