ABSTRACT
It is widely accepted that hematopoietic and endothelial cell lineages are initiated from the same precursor cells (named as hemangioblast), although hemangioblast has not been proved. Vascular endothelial growth factor (VEGF) and its receptor KDR/flk-1 is a prime regulator of endothelial cell proliferation, angiogenesis, vasculogenesis and vascular permeability. It is speculated that VEGF and its receptor KDR/flk-1 may also play an important role in embryonic and postnatal hematopoiesis. But the exact role and mechanism are not well known. Some latest developed cellular and molecular techniques can be used to prove the existence of hemangioblast and to investigate its biologic feature and the effect of VEGF and receptor KDR/flk-1 on its biologic feature.