1. University of Michigan, Ann Arbor, MI, USA
2. University of Southern California, Los Angeles, CA, USA
3. University of California–Berkeley, Berkeley, CA, USA
4. University of California–San Francisco, San Francisco, CA, USA
5. University of California–Davis, Davis, CA, USA
6. Stanford University School of Medicine, Stanford, CA, USA
7. Wyss Institute and Harvard University, Cambridge, MA, USA
8. University of Pittsburgh and the McGowan Institute for Regenerative Medicine, Pittsburgh, PA, USA
9. University of California–Los Angeles, Los Angeles, CA, USA