As methods for increasing stem cells are perfected and alternate regimens for transplantation developed, PSCT will undoubtedly see wider application in combination with BMT and may ultimately replace BMT. The initial encouraging results with PSCT so far portend a major therapeutic role of this modality in the approach to hematologic and oncologic diseases. Prospective randomized trials comparing PSCT and BMT in a variety of clinical settings are needed and are already underway.