Clinical outcomes of patients after nonmyeloablative umbilical cord blood transplantation who received Treg ≥ 30 × 105/kg (dotted line; n = 18) and historical controls (solid line; n = 108). (A) DFS (P = .25), (B) NRM (P = .51), (C) sustained donor engraftment (P = .89), and (D) grade II-IV aGVHD (P = .04).