American physician who in 1985 was the first to find the tumor angiogenesis factor predicted in 1961 by Judah Folkman. This factor is important to growing tumors because it stimulates the formation of new blood vessels that are needed to feed a growing tumor. One approach to combating cancer may be to inactivate this in growing tumors, causing them to starve for lack of food- and oxygen-carrying blood. Valle renamed this compound angiogenin.