Loss of 1 X chromosome in mice does not promote RUNX1-ETO–induced leukemia. (A) Schematic representation of retroviral constructs. MSCV indicates murine stem cell virus; LTR, long-terminal repeat; HA, hemagglutinin tag; and IRES, internal ribosome entry site. (B) Kaplan-Meier survival curve of animals transplanted with MigRE-transduced XO or XY cells. Pooled results from 6 different transplantation experiments are shown.