Disrupting the Zmiz1-Notch1 interaction impairs the DN-DP transition and T-ALL proliferation. (A-F) Representative CD4/CD8 flow cytometry plots (A,D), absolute total cell number counts (B,E), and DP (CD4⁺CD8⁺) cell counts (C,F) of transduced ΔLckCre cells after 6 days of culture in the OP9-DL1 assay described in Figure 4A. Cells counts are shown for 1000 seeded NGFR⁺ (A-C) or DsRed⁺ (D-F) DN3 cells. One-way ANOVA on log2-transformed values. (G-H) 20 000 transduced CD45.2⁺ DN3 cells were injected intrathymically into sublethally irradiated congenic CD45.1⁺ mice. After 10 days, the Dapi⁻CD45.2⁺CD45.1⁻NGFR⁺CD4⁺CD8⁺ (DP) cells were analyzed by flow cytometry (G) and shown as absolute numbers in scatterplot format (H). (I) Rosa26CreER^T2+Zmiz1^f/f T-ALL cells (#50 cells) were transduced with indicated Flag-tagged Zmiz1 mutants, sorted, and then cultured for with 6 nM 4-hydroxytamoxifen (OHT) for 6 days. Fold expansion represents the cell count on day 6 divided by day 0. (J) Rosa26CreER^T2+Zmiz1^f/f T-ALL cells (#50 cells, C5) were transduced with TPR-DsRed and cultured as in panel I. One-way ANOVA. *P < .05; **P < .01; ***P < .001; ****P < .0001.