Flow cytometric analysis of T cells cultured from E14.5 thymus. Cells were analyzed using monoclonal antibodies against CD4 and CD8. Numbers indicate the percentage of cells within each subcompartment: double-negative CD4⁻CD8⁻ (DN), double-positive CD4⁺CD8⁺ (DP), single-positive CD4 (CD4⁺SP), and single-positive CD8 (CD8⁺SP). *P < .05. ■ indicates wild type (n = 2); ▩, Asxl1^+/tm1Bc (n = 6); and □, Asxl1^tm1Bc/tm1Bc mutant (n = 7).