Described are methods of modulating stem/progenitor cell recruitment involving molecules that agonize the formation of plasmin stimulating the recruitment of stem/progenitor cells, including hematopoietic and endothelial precursor cells. Conversely, antagonists of plasmin can inhibit recruitment of the stem cells. In addition, the identification of the uPA receptor (uPAR) as a retention signal for stem cells in their niche suggests a novel method for increased engraftment and isolation of multipotent stem cells.