Paracrine signaling via platelet-derived growth factor B (PDGFB), expressed by endothelial cells, and its receptor PDGFR-beta, expressed by pericytes, plays a central role in blood vessel maturation. A new study (see the related article beginning on page 1142) reveals that it is not just the presence of PDGFB, but how it is presented to pericytes, that determines the quality of the endothelium-pericyte interaction.