Two recent studies investigating the use of human umbilical cord blood stem cell (UCB) transplants for lung and heart disorders in animal models found beneficial results. When human UCB-derived mensenchymal cells were transplanted into newborn laboratory rats with induced oxygen-deprived injury, the effects of the injury lessened. A second study found that UCB mononuclear cells transplanted into sheep with a right ventricular malfunction beneficially altered the malfunction and enhanced diastolic function.