1. Department of Radiology and Neurology, Stroke and Neurovascular Regulation Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
2. Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory for Experimental Hematology, Tianjin, China
3. Department of Radiation Oncology, University of Pittsburgh School of Medicine and Cancer Stem Cell Program, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, USA
4. Center for Regenerative Medicine, Massachusetts General Hospital, Harvard Medical School, Harvard Stem Cell Institute, Boston, Massachusetts, USA