1 Imperial College London, St. Mary's Hospital, Department of Infectious Disease, Section of Virology, Norfolk Place, London, UK.
2 International Institute of Molecular Mechanisms and Machines, Polish Academy of Sciences, Warsaw, Poland.
3 Department CIBIO, University of Trento, Povo-Trento, Italy.
4 Chemical Biology Laboratory, Centre for Cancer Research, National Cancer Institute, Frederick, MD, USA.
5 Retroviral Replication Laboratory, Centre for Cancer Research, National Cancer Institute, Frederick, MD, USA.
6 Chromatin Structure & Mobile DNA Laboratory, The Francis Crick Institute, London, UK.
7 LonCEM Facility, The Francis Crick Institute, London, UK.
8 Imperial College London, St. Mary's Hospital, Department of Infectious Disease, Section of Virology, Norfolk Place, London, UK. g.maertens@imperial.ac.uk.