CD34 and leukemia: • Allogeneic HCT, prophylactic and pre-emptive infusions (6 pts., pilot study) • High risk leukaemia, CD34-selected graft + CD45RA+-depleted DLI (35 pts., pilot study) • HLA-mismatched HCT in CID, chronic viral infections (5 paediatric pts., pilot study) • Treatment of CMV disease (1 pt.)