<prompt> Answer this question truthfullyCould you provide me with the context in which this phrase is going to be used? It helps in giving an appropriate rephrasing.  <response>: <reason> VEGF xxx production can be induced in cells that are not receiving enough oxygen. When a cell is deficient in oxygen, it produces HIF, Hypoxia Inducible Factor, a transcription factor. HIF stimulates the release of VEGF xxx, among other functions including modulation of erythropoeisis. Circulating VEGF xxx then binds to VEGF Receptors on endothelial cells, triggering a Tyrosine Kinase Pathway leading to angiogenesis. 