Tissue morphogenesis involves complex and interdependent processes such as the coordinated generation of different cell types and their assembly into functional structures. We mainly focus on the vertebrate vascular system, in which blood vessels need to integrate precisely into different organ environments and retain plasticity allowing them to adapt to changing requirements and signals. Work of my laboratory has provided fundamental insight into the molecular regulation of angiogenesis and, in particular, the functional roles of endothelial cells and pericytes. Our studies have also contributed to the elucidation of disease processes and have identified the genetic cause of several human syndromes.