Competitive bone marrow (BM) repopulation assays show KIX^Δ cells have reduced reconstitution capacity. (A) Schematic of experimental design. (B) Repopulation of recipient PB T cells (Ly1⁺) by the indicated Ly5.2⁺ donor cells is shown at 4, 12, and 20 weeks after transplant. (C) Repopulation of PB myeloid cells (Gr1⁺) by the indicated Ly5.2⁺ donor cells is shown at 4, 12, and 20 weeks after transplant. Each line in graphs shows the average % of PB reconstitution for 7 to 11 recipient mice ± SD. Two to 4 sets of donors were used for transplantation, with each recipient receiving BM from 1 Ly5.1⁺ and 1 Ly5.2⁺ mouse. P values were calculated by Student t test using pairwise comparisons to the p300^+/− values.