 These cells secrete high levels of CXCL12 and closely associate with sympathetic nerves that influence cytokine-induced migration of HSCs.Similar to these cells, CAR cells have correlated with reduced HSCs and LT-HSC activity when ablated.One difference between these cell types, despite the similarity in function, is that CAR cells may be found in both endosteal and perivascular niches, while nestin-positive MSCs are found exclusively in the perivascular niche.