The endosteum is a site of constant bone modelling and remodelling, and as such it is characterized by high concentrations of calcium ions (Ca2+). CaR is one receptor by which cells sense

the extracellular concentration of Ca2+, and because some haematopoietic cells have previously been shown to express CaR, Adams et al. set out to investigate whether CaR is important for HSC

localization or function in the endosteal niche. CaR was shown to be expressed by lineage (Lin)− stem-cell antigen 1 (SCA1)+KIT+ cells (known as LSK cells) isolated from the bone marrow, a

population that is enriched in cells with the functional properties of stem cells.