1. Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Croatia
2. Department of Pediatrics, University of Alabama Birmingham, Birmingham, Alabama
3. Hematopoiesis Unit, Nikolaus Fiebiger Institute for Molecular Medicine, University Erlangen-Nürnberg, Erlangen, Germany
4. Institute for Clinical and Molecular Virology, University Hospital Erlangen, Erlangen, Germany