Via Medical News Today, news of an advance in understanding of blood vessel formation: "Up till now, we've been looking for a 'missing link' in the process whereby blood-forming cells in the marrow head to the site of injury to rebuild and sustain the vasculature. [The protein stromal-derived factor 1 (SDF-1)] looks like it could be that missing link ... The finding could explain why [existing] therapies have only been partially effective in restoring proper blood flow to limbs affected by peripheral vascular disease. ... Without SDF-1, you've only got a part of the mechanism." Given the importance of blood vessel formation to tissue engineering and regenerative medicine, a full understanding of the mechanisms involved will assist a wide range of further research.