Our research explores the role of hypoxia-inducible factor (HIF) in tumorigenesis. HIF is a transcription factor that plays a key role in oxygen sensing, the adaptation to hypoxia and the tumor microenvironment. It is expressed in the majority of solid tumors and correlates with poor clinical outcome. Therefore, HIF is a likely promoter of solid tumor growth and angiogenesis. Our lab uses mouse models to ask if and how HIF cooperates with other oncogenic events in cancer. We are currently investigating HIF’s role in the upregulation of circulating tumor cells and circulating endothelial cells.