Walking the walk: Migration and other common themes in blood and vascular development

In this issue of Cell, a study by N. Cho and coworkers provides insight into the role of vascular endothelial growth factor (VEGF) signaling in Drosophila hematopoiesis (Cho et al., 2002). Their work suggests that an ancestral function of VEGF was to guide blood cell migration and highlights the conservation of at least one aspect of VEGF signaling during evolution.