 The relocalization of hemogenic endothelium coincides with the migration of distinct endothelial precursors to the AGM.Hematopoiesis then moves from the AGM to the placenta and fetal liver at E11.5 in mice and 5wpc in humans.While the engraftment of HSCs at these sites are still being elucidated, the interaction between the chemokine CXCL12 expressed by stromal cells and its receptor CXCR4 expressed on HSCs has been proposed as one mechanism.