Tet2 loss cooperates with AML1-ETO to induce leukemia in vivo. (A) Kaplan-Meier plot of mouse survival after transplantation with cells transduced with the given vector. WT pBEX (n = 5); WT AE (n = 10); WT AE9a (n = 7); Tet2 KO pBEX (n = 12); Tet2 KO AE (n = 23); Tet2 KO AE9a (n = 13). Tet2 loss significantly accelerates AE9a leukemias (P < 0.0001 using the Log-rank test). (B) Peripheral blood counts of mice transplanted with Tet2 KO cells expressing AE9a (n = 10), AE (n = 10), or pBEX (n = 5). Horizontal bars represent mean. (C) Representative hematoxylin and eosin staining (n = 3). Bars, 50 µm. (D) At euthanasia, leukemic mice exhibit significant splenomegaly compared with controls. Tet2 KO pBEX (n = 2); Tet2 KO AE (n = 9); Tet2 KO AE9a (n = 9). Error bars represent the standard deviation from the mean. (B and D) P-values were generated using the Student’s t test: *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. (E) Representative flow cytometry analysis of the bone marrow of transplant recipients (n = 10).