. The haplo graft usually establishes dominance and UCB chimerism is rarely detected. Comparison studies suggest considerably decreased rates of relapse and improved outcomes, compared with either haplo-identical transplant or CBU transplant, particularly in patients with advanced leukemia. A recent prospective randomized study confirms this. Haplo-cord mitigates the engraftment delay of UCB transplant. The unique biology of UCB grafts results in low GVHD and improved GVL especially beneficial in high-risk disease.