important areas for future investigation include the identification of optimal criteria for patient selection and timing of the therapy , the need for infusion of hematopoietic stem cells as cloned hematopoietic growth factors become available , the identification of the most effective high-dose regimens , and the need for `` '' purging '' '' tumor cells from the marrow before re-infusion .
C0018956
hematopoietic stem cells
C0007634
the