ABL1 inhibits expansion of BCR-ABL1–positive LSCs. (A) Mean percentage ± SD of GFP⁺Lin⁻c-Kit⁺Sca-1⁺ LSCs in freshly established (0 weeks) and 5-week-old (5 weeks) BCR-ABL1 Abl1^−/− and BCR-ABL1 Abl1^+/+ cells. (B) Mean percentage ± SD of quiescent LSCs (CPD^max Lin⁻c-Kit⁺Sca-1⁺), LT-LSCs (Lin⁻c-Kit⁺Sca-1⁺CD34⁻Flt3⁻), and ST-LSCs (Lin⁻c-Kit⁺Sca-1⁺CD34⁺Flt3⁻) in BCR-ABL1 Abl1^−/− and BCR-ABL1 Abl1^+/+ leukemia cell populations. (C) Bars represent mean percentage ± SD of GFP⁺Lin⁻c-Kit⁺Sca-1⁺ LSCs in BMCs isolated from moribund SCID mice transplanted with freshly established (0 weeks) and 5-week-old cultured (5 weeks) BCR-ABL1 Abl1^−/− and BCR-ABL1 Abl1^+/+ cells (see Figure 1). **P < .05, *P < .001 as determined by the unpaired Student t test; ns = not significant. (D) Statistically significant (false discovery rate [FDR] < 0.05) fold changes (>1.5) of expression of indicated genes regulating “stemness” in BCR-ABL1 Abl1^−/− vs BCR-ABL1 Abl1^+/+ leukemia cells maintained with SCF + IL-3.