5+6A method of treating a subject in need of a non syngeneic cell or tissue graft is disclosed. The method comprising: (a) transplanting into a subject a dose of T cell depleted immature hematopoietic cells wherein the T cell depleted immature hematopoietic cells comprise less than 5 x 10 CD3 T cells per kilogram body weight of the subject and wherein the dose comprises at least about 5 x 10 CD34+ cells per kilogram body weight of the subject； and subsequently (b) administering to the subject a therapeutically effective amount of cyclophosphamide wherein the therapeutically effective amount comprises 25 200 mg per kilogram body weight thereby treating the subject.
