Exchange transfusion is the replacement of blood from newborn infants with elevated bilirubin level in their blood stream with donor blood containing normal bilirubin levels. Newborn infants that experience jaundice, the yellowing of the skin and eyes, have a buildup of bilirubin, a chemical that occurs during red blood cell breakdown, or hemolysis. Exchange transfusion is a therapy developed throughout the 1940s by Louis Diamond and a group of surgeons at the Children’s Medical Center in Boston, Massachusetts. During exchange transfusion, a physician inserts a plastic tube called a catheter through the umbilical vein of the infant to slowly remove infant blood and sequentially replace it with donor blood. Exchange transfusion was the first definitive treatment for hyperbilirubinemia in the US and it helped reduce the incidence of kernicterus, a type of brain damage caused by elevated bilirubin levels.

Irving Lerner Weissman is a researcher and professor in developmental biology at the Stanford University School of Medicine in Stanford, California. Weissman is also a professor of pathology and Virginia & D. K. Ludwig professor of clinical investigation in cancer at the Stanford University School of Medicine. Weissman studies the biology of stem cells and immune cells and has conducted research in those fields during the late twentieth and early twenty-first centuries. In the late 1980s, Weissman’s team developed methods to identify hematopoietic stem cells, or HSCs, which give rise to the body’s blood and immune cells. Also, in the early 2000s, Weissman also co-authored California’s Proposition 71, which secured three billion dollars in state funding for stem cell research after the federal government restricted human embryonic stem cell work. Weissman’s efforts have demonstrated the therapeutic potential of stem cell transplantation in the treatment of diseases, including blood cancer.