Enhanced engraftment by sunitinib is transferable to secondary recipients. CD45.1⁻CD45.2⁺Rag1^−/− recipients received sunitinib or vehicle as described in Figure 1A, followed by transfer of 3.3 × 10⁴ electronically sorted HSCs from CD45.1⁺CD45.2⁻ C57Bl/6 mice on day 0. (A) Sunitinib recipients showed an increased percentage of donor-derived Gr-1 peripheral blood cells compared with vehicle recipients on day 25; N = 4 mice/group. (B) Sixty days after BMT, whole BM from recipients described in panel A was transferred to lethally irradiated CD45.1⁻CD45.2⁺ C57Bl/6 mice. (C) Frequencies of CD45.1⁺ cells in the recipients of the secondary transplantation are shown 7 months after the secondary transplantation: n = 8 for sunitinib group; n = 5 for vehicle group. Similar results were seen on day 32 and day 63 after the secondary transplantation. *P < .05. **P < .001.