1. BioTime, Inc., Alameda, CA 94502, USA
2. Burnham–Sanford Medical Research Institute, La Jolla, CA 92037, USA
3. Division of Immunology & Rheumatology, Stanford University School of Medicine, Stanford, CA 94305, USA
4. Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
5. BioTime, Inc., Alameda, CA 94502, USA.