1. Laboratory for Stem Cells & Aging, Buck Institute for Age Research, Novato, California, USA
2. Johns Hopkins Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
3. Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
4. Life Technologies, Carlsbad, California, USA
5. Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA