Chd7 deficiency delays Cbfb-MYH11–induced leukemia. (A-D) Mice were treated with ENU to induce mutations and then with poly(I:C) to induce the expression of Cbfb-MYH11 and/or Chd7 deficiency, and leukemia development in these mice was monitored. (A) Kaplan-Meier survival curves of mice with indicated genotypes during a 5-month observation of leukemia development. (B) Representative FACS plots of peripheral blood cells stained with c-Kit and Mac1. (C) Representative Wright-Giemsa–stained peripheral blood smears. (D) Representative hematoxylin and eosin–stained spleen sections (upper panel, ×50; bottom panel, ×400) from control, end-stage Mx1-CreCbfb^+/56M, and Chd7^f/fMx1-CreCbfb^+/56M mice. (E) Kaplan-Meier survival curves of mice transplanted with 1 million spleen cells from end-stage Mx1-CreCbfb^+/56M and Chd7^f/fMx1-CreCbfb^+/56M mice. *P < .05; ***P < .001, each comparing the Chd7^f/fMx1-CreCbfb^+/56M group with the Mx1-CreCbfb^+/56M group.