1. Center for Regenerative Medicine in Barcelona, CMR[B], Dr Aiguader 88, 08003, Barcelona, Spain.
2. Functional Genomics Core Facility, Institute for Research in Biomedicine, Parc Científic de Barcelona, Baldiri Reixac 10, 08028 Barcelona, Spain.
3. Gene Expression Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 93027, USA.