1. Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 142 20 Prague, Czech Republic
2. Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland
3. Genome Integrity Unit, Danish Cancer Society Research Center, 2100 Copenhagen, Denmark
4. Department of Medical Biochemistry and Biophysics, Karolinska Institute, 17177 Stockholm, Sweden