Tubulogenesis during blood vessel formation

► Endothelial lumens are required for proper formation and function of the circulatory system. ► Diverse cellular mechanisms for lumen formation are used in different vascular beds. ► Control of cell adhesion, deadhesion, polarity and internal contractility is critical to lumen formation. ► Rasip1 and Rho family GTPases are essential modulators of lumen formation.