California Institute for Regenerative Medicine, Berkeley, CA 94720-3370, USA;
Howard Hughes Medical Institute, Berkeley, CA 94720-3370, USA;
University of California, Berkeley, CA 94720-3370, USA;
California Institute for Regenerative Medicine, Berkeley, CA 94720-3370, USA;
Howard Hughes Medical Institute, Berkeley, CA 94720-3370, USA;
University of California, Berkeley, CA 94720-3370, USA;