1. Department of Biochemistry, New York University School of Medicine, 522 First Avenue, New York, New York 10016
2. Mammalian Developmental Epigenetics Group, CNRS UMR218, Nuclear Dynamics and Genome Stability, Institute Curie, 26 Rue d'Ulm, 75248 Paris Cedex 05, France
3. Center for Advanced Biotechnology and Medicine, Department of Pediatrics, UMDNJ—Robert Wood Johnson Medical School, Piscataway, New Jersey 08854
4. Departments of Medicine and Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University College of Physicians and Surgeons, New York, New York 10032
5. Institut de Génétique et de Biologie Moléculaire et Cellulaire, UMR 7104, CNRS, INSERM, ULP, CU de Strasbourg, 67404 Illkirch, France
6. Howard Hughes Medical Institute