1. Laboratory of Reliability and Quality Control in Laboratory Hematology (HemQcR), Department of Biomedical Sciences, Section of Medical Laboratories, School of Health & Caring Sciences, University of West Attica (UniWA), Ag. Spyridonos Str., 12243 Egaleo, Greece
2. First Department of Internal Medicine, 417 Army Share Fund Hospital, 11521 Athens, Greece
3. 2nd Academic Department of Internal Medicine, Medical School, National and Kapodistrian University of Athens, Hippokration General Hospital of Athens, Vasilissis Sofias Avenue Str., 11527 Athens, Greece
4. Oncology Department, General Hospital Evangelismos, 10676 Athens, Greece
5. Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
6. Second Department of Internal Medicine, 401 General Military Hospital, 115 27 Athens, Greece
7. Department of Biochemistry, School of Medicine, University of Patras, 26504 Patras, Greece
8. Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA