1. Emilia Romagna Cord Blood Bank, Immunohaematology and Transfusion Medicine, St. Orsola-Malpighi University Hospital, Bologna, Italy.
2. Unit of Histology, Embryology and Applied Biology, Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
3. Otolaringology Unit, St. Orsola-Malpighi University Hospital, Bologna, Italy.
4. Unit of Surgical Pathology, Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.