The review is devoted to angiogenin, one of the factors that induce formation of 
blood vessels, which is unique among them in that it is a ribonuclease. 
Consideration is given to the tertiary structure of human angiogenin; the 
catalytic and cell-receptor binding sites, their significance for angiogenic 
activity; the human angiogenin gene structure, chromosomal localization, and 
expression; the specificity of angiogenin as a ribonuclease and abolishment of 
protein synthesis; the nuclear localization of angiogenin in proliferating 
endothelial cells and its significance for angiogenic activity; angiogenin 
binding to a cell-surface actin as a plausible mechanism of inducing 
neovascularization (enhancement of plasminogen activation by actin with 
angiogenin, stimulation of the cell-associated proteolytic activity by 
angiogenin; promotion of the cultured cells invasiveness); modulation of 
mitogenic stimuli in endothelial, smooth muscle, and fibroblast cells by 
angiogenin. The importance of angiogenin as an adhesive molecule for endothelial 
and tumor cells is discussed too, as well as the modulation of tubular 
morphogenesis by bovine angiogenin, prevention of tumor growth in vivo by 
angiogenin antagonists, prospects of the use of angiogenin and 
angiogenin-encoding recombinant plasmids and vaccinia virus in therapeutic 
practice.