Cotransplantation of MSCs may result in higher engraftment in double cord blood transplantation because of alleviation of donor-deviated engraftment. (A) Total engraftment of cord blood cells achieved by double cord transplantations in the presence or absence of MSC cotransplantation. Multiple independent cohorts of double cord transplantations were performed by transplanting total MNCs equivalent to 3 × 10⁴ CD34⁺ cells for each UCB unit in the presence (n = 19) and absence (n = 26) of 4 × 10⁴ MSCs. Shown are the mean engraftment levels ± SEM of human cord blood cells in NOD/SCID mice. (B) Lineage distribution of human cells engrafted in the NOD/SCID mice in the presence or absence of MSC cotransplantation. Shown are the mean percentages of the total human cell engraftment (CD45/71) of each lineage (with SEM, n = 8 each).