ABSTRACT
Growth of solid tumors and the formation of metastases are dependent on the formation of new blood vessels. This hypothesis was proposed by Judah Folkman more than 25 years ago and has been substantially supported by recent discoveries which unraveled the molecular and cellular processes involved in tumor angiogenesis. Clinical data clearly indicate the correlation between vascularization and aggressive tumor growth and metastases formation. Many of the angiogenic factors produced by tumors have been identified and their roles in the formation of new blood vessels have been elucidated (Folkman 1995).
