Abstract : Mesenchymal stem cells (MSC) reside in the stromal compartment of the hematopoietic bone marrow. Although present in small numbers in vivo, MSC may be easily isolated and expanded in cell culture. MSC are able to generate bone, cartilage, fat, and under specific conditions, liver, muscle and nerve. Numerous studies have suggested a potential use of MSC to repair degenerative or traumatic lesions, in organs where tissue repair is limited. Furthermore, MSC are endowed with immunosuppressive properties, utilized to control graft versus host disease and rejection of allogenic hematopoietic stem cell transplants.