1. Blood and Marrow Transplantation, Stanford University School of Medicine, Stanford, CA 94305, USA.
2. Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
3. Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
4. Ludwig Center for Cancer Stem Cell Research and Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
5. Department of Pathology, Stanford University Medical Center, Stanford, CA 94305, USA.