1. Institute of Oncology Ljubljana, Zaloška 2, Sl-1000 Ljubljana, Slovenia
2. Institute of Histology and Embryology, Faculty of Medicine, University in Ljubljana, Vrazov trg 2, Sl-1000 Ljubljana, Slovenia
3. General Hospital Rakičan, Ulica dr. Vrbnjaka 6, Sl-9000 Murska Sobota, Slovenia
4. General Hospital Slovenj Gradec, Gosposvetska Cesta 1, Sl-2380 Slovenj Gradec, Slovenia