The National Marrow Donor Program (NMDP) / Center for International Blood and Marrow Transplant Research (CIBMTR) is trying to learn more about what makes bone marrow, blood stem cell and cord blood transplants work well. The purpose of storing a blood sample from either related or unrelated donors and their recipients in the NMDP/CIBMTR Research Sample Repository is to provide cells for researchers to study. Although the exact study for which samples may be used is not known at this time, the following are types of studies in which these data may be included. These are studies to:

• Improve the understanding of tissue matching for related and unrelated donors and recipients
• Determine and evaluate the factors that affect transplant outcome
• Study the distribution of tissue types in different populations; e.g., study tissue typing differences between different racial and ethnic populations to help develop methods that will improve tissue matching between donors and recipients.