1. Department for Cytopathology, Heinrich-Heine-University Düsseldorf, D-40225 Düsseldorf, Germany
2. Department for Pediatric Hemato-Oncology, Helios Children’s Hospital, D-47805 Krefeld, Germany
3. Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, PL-10-748 Olsztyn, Poland
4. School of Medicine, Institute of Biomedicine, University of Eastern Finland, FI-70211 Kuopio, Finland