1. Centre Development in Stem Cell Biology, Institute for Stem Cell Research,School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
2. Institut de Recherche en Immunologie et en Cancérologie, and Department of Pharmacology, Université de Montréal, Montréal,Québec, Canada.
3. Wellcome Trust Centre for Stem Cell Research, and Department of Biochemistry,University of Cambridge, Cambridge, UK.