Looks like it's the endothelium that is pivotal to angiogenesis. Angiogenesis is important for revascularization, including building collaterals where flow is abnormal. The reverse is also true – when healthy flow is restored, revascularization creates better perfusion through the body's tissues. That's another reason to keep your blood vessels healthy and follow Joan's endothelial health program!

Many of us with neurovascular illnesses and symptoms recently discovered we have collateral veins. Tissues that have blood flow in a manner not well accommodated by our bodies undergo a process called angiogenesis to develop new blood vessels. Here's new research showing how this process works:
http://www.medicalnewstoday.com/releases/308593.php