About the Authors
Department of Developmental Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany
Department of Biology, Chemistry, and Pharmacy, Free University Berlin, Berlin, Germany
Institute for Medical Genetics, Charité – University Medicine Berlin, Berlin, Germany
The authors have declared that no competing interests exist.
Conceived and designed the experiments: BGH HB. Performed the experiments: HB JW SS BK YC. Analyzed the data: BGH HB SS YC. Wrote the paper: BGH HB.