Better control over the growth of blood vessels, or angiogenesis, is required for continued progress in tissue engineering. It could be a novel avenue for regenerative medicine. Reversing blood vessel growth will be most useful in fighting the growth of cancer in the body. Here, Medical News Today reports on progress towards that control: scientists have discovered "a switch inside blood vessel cells that controls angiogenesis ... Angiogenesis is an important natural process that can be both good and bad for the body. It restores blood flow after injury [and] increases circulation in a damaged heart. But, it can also nourish cancer tumors and damage delicate retinal tissues when uncontrolled. ... Understanding this process opens a whole new avenue for treatment of angiogenesis-related diseases. For instance, drugs could be designed to decrease [a switching enzyme] in cancer patients or those with proliferative diabetic retinopathy or macular degeneration, or designed to increase it in a damaged heart."