- First-degree relatives of patients evaluated for stem cell transplantation will be eligible if: (1) Willing to undergo testing for HIV and hepatitis B and C (free of charge) (2) Not pregnant at time of collection of blood (3)In good general health (4) No prior history of malignancy. (5) Age 18 years or older if donating apheresis product. (Because of the relatively invasive nature of the leukopheresis procedure and difficulties in obtaining consent, children <18 who are first degree relatives of the patient will not undergo apheresis for studies on this protocol)