Some 35 years ago, from an accidental observation made as a young researcher, he divined that tumors must somehow induce the body to build the blood vessels that feed them.

It was this observation that led him to suppose that growing tumors must induce their own blood supply, probably through secreting some factor into the surrounding tissue.

In 1973 he showed that tumors inserted in the clear cornea of a rabbit's eye would visibly induce blood vessels to grow toward them.

The finding could be important for cancer therapy, because solid tumors must induce new blood vessels to form around them when they grow beyond a certain size.

Because tumors induce rapid and uncontrolled angiogenesis they are especially "leaky" and allow liposomes to exit the bloodstream at a much higher rate than normal tissue would.

To grow beyond a certain size, tumors must induce a nearby blood vessel to sprout new branches that will supply them with oxygen and nutrients.

A negative family history can be useful in distinguishing tumor induced osteomalacia from XHR and ADHR.

Cancerous tumors also actively induce immune tolerance, which prevents the immune system from attacking them.

But Dr. Folkman said that according to his experiments, even established tumors have a rapid turnover of blood vessels and must continually induce the body to build new ones.

Matrix digestion by MMPs, including MMP-1, MMP-2, and MMP-9, is a pre-requisite for EC activation, differentiation, and tumor induced angiogenesis [ 16 17 ] .