1. Department of Pathology, Aeghion General Hospital, 25100 Aeghion, Greece
2. Department of Biological Chemistry, Medical School, University of Athens, 115 27 Athens, Greece
3. Division of Hematology/Oncology, University of Pittsburgh, Pittsburgh, PA 15232, USA
4. Department of Histology/Embryology, Democritus University of Thrace, 68 100 Alexandroupolis, Greece
5. Division of Hematology and Oncology, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA