This is a type of treatment for bone marrow failure diseases such as aplastic anaemia. 

The patient is given drugs such as chemo-therapy and/or ATG before the transplant to weaken the immune system, thus allowing the bone marrow to accept donor stem cells. The healthy stem cells are transfused into the patient. This is the only treatment used in the cure of severe or very severe aplastic anaemia, but it is the most invasive.