1. Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University, New York, NY 10065, USA.
2. Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
3. Departments of Pediatrics and Pathology, Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, NC 27710, USA.
4. Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.