Haemopoiesis occurs in the BM, where haemopoietic stem cells (HSC) reside in a three-dimensional “niche” and give rise to the millions of circulating blood cells required everyday of life. The precise regulation of this immense task occurs by interaction of HSC with other BM cells and extracellular matrix molecules. In addition, the BM vasculature has also now been identified as a key HSC regulator. ...