Thymocyte development in TCF-1-deficient mice. (A) Density plots show a representative analysis of CD4/CD8 and CD44/CD25 subsets among lin^- thymocytes (cells not expressing CD4, CD8, CD3, B220, CD11b, TCRβ, TCRγδ, NK1.1, Gr1, and Ter119). Numbers indicate the percentage of cells in the respective gate. (B) Bar graphs show the mean ± SD of the absolute number of cells of the indicated type; DN1 indicates lin^- CD44⁺CD25^-/low, DN2, lin^- CD44⁺CD25^hi; DN3, lin^- CD44^-CD25^hi; DN4, lin^- CD44^-CD25^neg. Histograms show the expression of CD117 (c-kit) and CD127 (IL-7 receptor α [IL-7Rα]) (C), intracellular TCRβ (D), or CD3ϵ (E) and TCRγδ (F) in the indicated lin^- population. Numbers indicate the percentage of cells in the regions defined by horizontal bars. (G) Bar graphs show the mean of the absolute number of cells of the indicated type (± SD).