<unk>  <unk>  is the transplantation of multipotent<unk>  stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood in order to replicate inside of a patient and to produce additional normal blood cells. It may be autologous (the patient's own stem cells are used), allogeneic (the stem cells come from a donor) or syngeneic (from an identical twin). It is most often performed for patients with certain cancers of the blood or bone marrow, such as multiple myeloma or leukemia. In these cases, the recipient's immune system is usually destroyed with radiation or chemotherapy before the transplantation. Infection and graft-versus-host disease are major complications of allogeneic<unk> .<unk>  remains a dangerous procedure with many possible complications; it is reserved for patients with life-threatening diseases. As survival following the procedure has increased, its use has expanded beyond cancer to autoimmune diseases and hereditary skeletal dysplasias, notably malignant infantile osteopetrosis and mucopolysaccharidosis.
Hematopoietic stem cell transplantation
Syngeneic stem cell transplantation
Stem-cell therapy
Peripheral stem cell transplantation
Autologous stem-cell transplantation
Thymus transplantation
Autologous immune enhancement therapy
Spleen transplantation