BioEssays 3∕2014

The cord‐to‐tube transition . The assembly of blood vessels in the vertebrate embryo requires a series of coordinated steps, amongst them lumen formation. On pages 251–259, Charpentier and Conlon review the most recent data on the diverse mechanisms by which vascular lumens arise, as well as the molecular and cellular players that contribute to this complex process. The cover depicts the inherent heterogeneity of blood vessel structure, which can be made up of both unicellular (represented by pink and blue colored cells) as well as multicellular (represented by green/yellow and red/brown colored cells) tubes. Remodeling of this cellular architecture is critical as new vessels form and new vascular connections are made.