 To carry out an unrelated transplant, a normal person with similar HLA type must be available to donate cells. The patient must be prepared to accept the donor cells by decreasing the bodys immune systems. In addition, the malignant cancerous cells must be destroyed to allow growth and repopulation of healthy donor cells. This is usually done by giving total body irradiation and chemotherapy, which is associated with severe side effects in patients over age 40. 