MOLECULAR ASPECTS OF ENDOTHELIAL CELL FUNCTION AND HYPOXIA-DEPENDENT TUMOR ANGIOGENESIS
Hypoxia, or deficient oxygen levels, is an inherent feature of rapidly expanding tumor tissue. In order to survive in the hostile, hypoxic environment and to restore the supply of oxygen and nutrients tumor cells activate a variety of adaptive mechanisms. Among them, hypoxia-induced angiogenesis, i.e. the formation of tumor blood vessels from pre-existing vasculature, has proved to be of critical