Function of Prdm16-deficient HSPCs. (A-C) Ratio between donor (300 Prdm16^−/− or wt FL LSK cells (n = 4) (A), 500 Prdm16^+/− or wt adult BM LSK cells (n = 9) (B), or 300 Prdm6^+/− or wt adult BM LSKCD34⁻Flt3⁻ cells (n = 4) (C) and competitor (0.5 × 10⁶ T cell-depleted CD45.1⁺ or CD45.1⁺CD45.2⁺ B6 BM cells) cells among PB myeloid and B cells, and (C) thymic CD4⁺CD8⁺ double-positive and CD4⁻CD8⁻ double-negative developing T cells, 10 to 15 weeks after transplantation into lethally irradiated B6.129F1 (CD45.2⁺) mice. *P < .01. (D) Representative example of donor (CD45.2⁺) and competitor (CD45.1⁺CD45.2⁺) reconstitution in doublet discriminated PB CD19⁺ B and Mac1⁺Gr1⁺ myeloid cells, and in thymic CD4⁻CD8⁻ double-negative and CD4⁺CD8⁺ double-positive cells after competitive transplantation with wt or Prdm16^+/− adult BM LT-HSCs.