Understanding mechanisms of human vascular regeneration: For decades, isolated endothelial cells have served as model system to study the effect of growth factors and inhibitors. The Groups of J. Bischoff & D. Strunk demonstrated that co-transplantation of human endothelial colony-forming cells (ECFCs) with various pericyte precursor populations results in most robust vessel formation in vivo. Both laboratories interact to better understand human vascular regeneration eventually creating novel therapy strategies.