Abstract
How endothelial cells adapt their metabolism to the rising energy and biomass demands of sprouting vessels is an exciting field of research in vascular biology with numerous open questions. Two new studies published in this issue of The EMBO Journal now show the importance of glutamine in endothelial metabolism, required to sustain endothelial cell proliferation and vascular expansion. These results provide insight into how endothelial cells selectively use nutrients for energy and biomass production and illuminate new levels of regulation of the angiogenic process.