1. Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
2. Harvard Stem Cell Institute, Cambridge, MA 02138, USA.
3. Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA.
4. Cardiovascular Developmental Biology Department, Centro Nacional de Investigaciones Cardiovasculares, 28029 Madrid, Spain.
5. Advanced Microscopy Program, Center for System Biology and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA.
6. Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA.
7. Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
8. Department of Hematology and Bone Marrow Transplantation, University of Parma, Parma 43126, Italy.
9. Department of Internal Medicine and Biomedical Science, University of Parma, Parma 43126, Italy.
10. Ruth L. and David S. Gottesman Institute for Stem Cell and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA.