For many years, allogeneic bone marrow transplantation has been used to successfully treat leukemias, other hematologic conditions and congenital disorders. The first unrelated donor transplants were performed in the late 1970s, but this procedure did not become widely available until the development of several consolidated unrelated donor registries around the world. The National Marrow Donor Program, established in 1987, is the world's largest registry and currently lists more than 7 million donors. Since its beginning, NMDP has facilitated more than 30,000 unrelated transplants.