Current understanding of stem cell mobilization Tsvee Lapidot, Isabelle Petit  Experimental Hematology  Volume 30, Issue 9, Pages 973-981 (September 2002) DOI: 10.1016/S0301-472X(02)00883-4

Figure 1 A model for stem cell mobilization by G-CSF. In steady state (upper panel), stem cells are localized in close proximity to stromal cells. Retention is mediated by adhesion molecules such as VCAM-1/VLA-4 and through SDF-1/CXCR4 interactions. During mobilization (lower panel), G-CSF induces both cell proliferation and release of neutrophil proteases (elastase, cathepsin G, and MMPs), which participate in cell egress by degrading retention signals (VCAM-1 and SDF-1) and by remodeling the extracellular matrix. Upregulation of CXCR4 on BM cells during G-CSF-induced mobilization suggests active participation of SDF-1/CXCR4 interactions in the migration of cells towards the blood. Experimental Hematology 2002 30, 973-981DOI: (10.1016/S0301-472X(02)00883-4)