ABSTRACT
INTRODUCTION The vascular supply is commonly regarded as a significant factor in the development of both benign and malignant tumors. On the one hand, the nutrient supply they require for growth must be provided via an adequate vascular network in order for the tumors to expand, and poorly vascular or avascular tumors are severely restricted in their growth potential. On the other hand, the dynamics of growth and - in case of malignant tumors - the metastatic activity depends, among others, on the intensity of angiogenesis, providing new vessels for the developing tumor. Frequently, tumors overex press proangiogenic factors, showing dysregulation of the local balance of proangiogenic and antiangiogenic substances.
