Vascular endothelial growth factor (abbreviated VEGF and pronounced "Veg-F") is a peptide signaling molecule related to platelet-derived growth factor. VEGF is important in the formation of the circulatory system because its signaling pathway causes the formation of new blood vessels in developing embryos during normal development. Tumors also produce and secrete VEGF, causing the formation of new blood vessels that supply these tumors.

Given what you know about the different kinds of cell signaling andabout VEGF, is VEGF a paracrine or an endocrine-signaling molecule? Justify your answer.