Ithasbeendemonstratedthattbecriticalroleofbonemarrowstromalcells(HMSCs)istosustaintheselfrenewalofpluripotenthematopoieticstemcellsandmaintainthehomeostasisofbonemarrowhematopoiesismicroenvironment.BMSCprogenitorcandifferentiateintoseveralclementsincludingmacrophages,endothelialcells,fibroblastsandsomeothercells.Almostall