It is clear that reduced intensity allo-SCT regimens can result in reliable donor engraftment with a relatively low mortality compared with high-dose regimens. The immunologic effect of the allograft is, however, relatively modest requiring a prior autologous transplant for cytoreduction. Even with the tandem auto-non-myeloablative allo-SCT approach, relapses beyond 3--5 year continue to occur, making disease recurrence the primary cause of treatment failure after tandem auto, non-myeloablative allo-SCT.