Dr. Geoffrey C. Gurtner is a surgeon-scientist whose research in vascular biology has advanced our understanding of how new blood vessels form following tissue injury and ischemia. He has explored how bone marrow derived progenitor cells contribute to this process and augment the classical pathways of angiogenesis. This work has focused on the mechanisms through which distant hypoxic events are able to stimulate the mobilization and recruitment of bone marrow derived cells to areas of tissue injury. Dr. Gurtner was the first to demonstrate that low oxygen tension and HIF-1a were able to transcriptionally regulate the chemokine stromal derived factor-1 (SDF-1), a central mediator of progenitor cell trafficking. This was a surprising finding since no chemokine had previously been shown to be hypoxia responsive but has since been confirmed in over 60 independent publications. Dr. Gurtner has extended this work to more fully define the linear relationship between oxygen tension and progenitor cell recruitment in ischemia models, demonstrating that bone marrow cells are able to incorporate into the endothelium of new vessels predominantly in the areas of maximal HIF-1a stabilization. Finally, Dr. Gurtner has led efforts to clarify how HIF-1a dysfunction may be a central mediator of impaired neovascularization in conditions such as diabetes and aging and has demonstrated that targeting HIF is an effective strategy to reverse these defects.