ABSTRACT
Angiogenesis, defined as the growth of new capillaries from preexisting vessels, is a pervasive biological phenomenon that is at the core of many physiological and pathological processes. Examples of physiological processes which depend upon angiogenesis include embryogenesis, wound repair, and the ovarian/ menstrual cycle. In contrast, chronic inflammation associated with chronic fibroproliferative disorders as well as growth and metastasis of solid tumors are associated with aberrant angiogenesis. Angiogenesis is similar to, but distinct from, vasculogenesis, which describes the de novo formation of the vascular system from precursor blood islands during embryogenesis. Development of the heart and great vessels occurs via vasculogenesis, whereas organs which require invasion of blood vessels for development (brain, lung, kidney) are supplied by angiogenesis (1). Neovascularization is a term which can be used interchangeably with angiogenesis, but may be more appropriately reserved for describing aberrant angiogenesis which accompanies pathological, processes such as tumorigenesis or chronic inflammation.
