Approximately 8000 patients per year with multiple myeloma (MM) receive a stem cell transplant in the United States. Ten years ago, the number of transplants were about 5,550. MM is a cancer that affects plasma cells in the bone marrow, causing them to divide rapidly. While melphalan is currently the standard of care, it has been shown that a combination of melphalan+busulfan may be superior to a treatment of melphalan monotherapy. In a recent clinical trial, the median Progression Free Survival for the melphalan+busulfan combination was 64.7 months versus 43.5 months for the melphalan alone group.