CSF3 and viral infectious disease: Treatment with donor lymphocyte infusions (DLI) routinely separated from the seropositive stem cell donor can improve the clinical outcome of viral infection and leukaemia relapse, but it is (i) associated with a high risk of inducing graft-versus-host disease (GvHD), (ii) attended with impaired functionality of antiviral memory T cells in granulocyte colony-stimulating factor- (G-CSF-) mobilized stem cell donors [13-15], (iii) not suitable in high risk patients with seronegative donors and (iv) not available for patients receiving cord blood in HSCT or cadaveric transplants in SOT.