The growth of new capillaries from existing vessels (angiogenesis) is of fundamental importance in wound healing and in pathological situations such as proliferative diabetic retinopathy (1 ), rheumatoid arthritis (2 ), and tumor growth. Consequently, considerable interest in vascular cell biology has arisen in apparently disparate clinical and experimental fields. Held in common, however, is the hope that an understanding of the cellular and molecular mechanisms that regulate angiogenesis will lead to novel therapeutic agents and targets.
