Reduced destruction of recipient bone marrow cells in B6D2F1 mice receiving GKO allo-HCT. B6D2F1 mice received 6 Gy TBI one day before administration of 2 × 10⁷ allogeneic splenocytes alone or along with 10⁷ BMCs from WT or GKO B6 donors (n = 6 per group). Non-HCT controls were sublethally irradiated B6D2F1 mice receiving no transplantation (n = 3). BMCs were prepared at days 5 and 10, and percentages of recipient-type (H-2d⁺) cells were determined by flow cytometry. The total number of recipient-type BMCs was calculated as the product of the percentage of host-type cells and the total bone marrow cellularity. Shown are numbers (mean ± SD) of host-type nucleated cells in bone marrow. *P < .05; **P < .01.