Hematopoietic chimerism will be investigated from PB samples. Prior to transplant 5 ml EDTA PB from patient and donor are required and will be sent to the laboratory of the Coordinating Investigator (P.B.). Post transplant PB samples (5 -10 ml EDTA blood) from day +30 (4 days), +60(4 days), +100 (7 days) and +180 (7 days) will also being sent to the laboratory of the Coordinating Investigator (P.B.) From EDTA PB cell subpopulations will be isolated and DNA will be extracted and stored for further investigations.