CUX1-deficient HSPCs have an impaired DNA damage response and unrepaired DNA damage in vivo. (A) Bone marrow (BM) was collected from Ren, Cux1^mid, and Cux1^low mice after treatment with Dox for 7 days. The cells were irradiated ex vivo (2 Gy) and γH2AX induction was measured by intracellular flow cytometry at 30 minutes, 1 hour, 4 hours, and 6 hours after irradiation. LSK cells were gated, and γH2AX MFI was normalized to the 0-hour timepoint from each experiment. Representative histograms of γH2AX staining 1 hour after irradiation in LSKs and total lineage-negative cells are shown. Plot is the result of 3 independent biological replicates. Data are shown as mean ± standard deviation (SD) with P values from a 2-way analysis of variance (ANOVA). (B) Ren, Cux1^mid, and Cux1^low mice were treated with Dox for 7 days and subsequently irradiated in vivo (6 Gy). Bone marrow was collected at 6 and 24 hours postirradiation, and Kit⁺ cells were isolated for a neutral comet assay. Representative images are shown (right). Mean ± standard error of the mean (SEM) is shown for 3 biological replicates. Mann-Whitney test, *P < .05; **P < .01; ***P < .001; ****P < .0001.