1. Institute of Molecular Life Sciences of the University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
2. Institute of Molecular Cancer Research of the University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
3. Institute of Biochemistry of the Swiss Federal Institute of Technology, Otto-Stern-Weg 3, 8093 Zurich, Switzerland
4. Department of Genome Dynamics, Institute of Molecular Genetics of the Czech Academy of Sciences, 142-20 Prague 4, Czech Republic
5. Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
6. Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, 606-8501 Kyoto, Japan