E2F1 regulation in CML SPCs by BCR-ABL1. (A) Nuclear levels of E2F1 mRNA measured in healthy and CML CD34⁺38⁻ and CD34⁺38⁺ cells by Q-PCR. (B) Phosphorylation level of Rb measured in healthy and CML SPCs by a high-content screening-based platform. (C) mRNA levels of E2F1 downstream genes measured in healthy and CML CD34⁺38⁻ and CD34⁺38⁺ cells by Q-PCR. (Di) Heatmap showing regulation of E2F1 and its signaling (yellow, upregulation; blue, downregulation, see color bar) in CML SPCs after treatment with TKIs (values for imatinib, dasatinib, and nilotinib pooled together) for 7 days (treated columns indicated by “+”). (ii) E2F1 response to TKI treatment of 8 hours and 7 days. (E) E2F1 and CDK1 mRNA levels from CML SPCs treated with dasatinib (DAS, 150 nM) or washed out and cultured for a further 3 days (DAS w/o). ●, Outliers as calculated using the Tukey method.²⁴  Each experiment had N = 3 biological replicates. *P < .05; **P < .01; ***P < .001. RMA, robust multiarray average.