Contents

19 October 2001
Vol 294, Issue 5542

About The Cover

Cover image expansion

COVER Confocal image showing the close association of immature pancreatic islets of Langerhans (green fluorescence) with blood vessels (red fluorescence) during embryogenesis; cell nuclei are blue. Blood vessels induce the formation of the islets during development, which leads to the intimate contact that allows islets to secrete insulin directly into the bloodstream in response to blood glucose levels. 564 [Image: Ondine Cleaver]