Anxa2 regulates stem cell homing to bone marrow. Fluorescently labeled bone marrow mononuclear cells were transplanted via intravenous injection into nonablated mice that had been inoculated with either a N-terminal Anxa2 peptide or a scrambled control at a concentration of 10 μg/kg (0.2 μg/animal). The percentage engraftment of the transplanted cells was quantified at 24 hours by FACs analysis by gating on 106 cells. *P < .05 versus the control. The data demonstrate that blocking Anxa2 results in fewer labeled cells in the marrow.