Mesenchymalstromalcells(MSCs)areadultmultipotentstemcellsresidingaspericytesinvarioustissuesandorganswheretheycandifferentiateintospecializedcellstoreplacedyingcellsanddamagedtissues.Thesecellsarecommonlyfoundatinjurysitesandintumorsthatareknowntobehavelike'woundsthatdonotheal.'Inthisarticle,wediscussthemechanismsofMSCsinmigrating,homing,andrepairinginjuredtissues.WealsoreviewanumberofreportsshowingthattumormicroenvironmenttriggersplasticitymechanismsinMSCstoinducemalignantneoplastictissueformation,maintenance,andchemoresistance,aswellastumorgrowth.TheantitumorpropertiesandtherapeuticpotentialofMSCsarealsodiscussed.