1. National Institute of HaematologyBlood Transfusion and ImmunologyBudapestHungary
2. 1st Institute of BiochemistrySemmelweis Medical UniversityBudapestHungary
3. National Cancer InstituteNational Institutes of HealthBethesdaMaryland20892USA
4. The University of North Carolina at Chapel HillChapel HillNorth Carolina27599USA