to investigate the effects of FK506 on the course of EBV infection in vivo Overall design: we reconstituted NOD-scid IL2Rγc−/− HLA-A2 transgenic mice with CD34+ hematopoietic progenitor cells (HPC) from HLA-A2+ human fetal livers. Upon assessment of human immune cell reconstitution in the peripheral blood at three to four-months after HPC injection, mice were infected with EBV (strain B95-8) or mock-infected with PBS. Three weeks post-infection (p.i.), animals were either treated with subcutaneous (s.c.) injections of FK506 (Tacrolimus) every second day or left untreated for a further two weeks.