Researchers say that cord blood from the umbilical cords of recently delivered babies may prove to be a good source of stem cells for transplant in the treatment of diseases like leukemia and lymphoma. Bone marrow and the bloodstream are currently sources for these stem cells. But doctors say stem cells from cord blood may not require as close a tissue match. Right now, not all of the people who might benefit from transplants are able to undergo the procedure because perfect tissue matches with a potential donor cannot be found.