HIF1α deletion suppresses LSCs. (A) FACS analysis of LSCs in BM of secondary recipients of WT or HIF1α^−/− BM cells from primary CML mice. (B-C) The percentages and total numbers of stem cells (GFP⁺Lin⁻Sca-1⁺c-Kit⁺ cells and GFP⁺CD48⁻CD150⁺Lin⁻Sca-1⁺c-Kit⁺ cells) in BM of secondary recipient mice receiving BM cells from WT or HIF1α^−/− control and CML mice were analyzed by FACS; *P < .05; **P < .01. (D) The loss of HIF1α causes a decrease in the colony-forming ability of BCR-ABL–expressing LSK cells. Sorted normal LSK cells and BCR-ABL–expressing LSK cells (GFP⁺Lin⁻Sca-1⁺c-Kit⁺ cells) were plated into methycellulose medium, colonies were counted, and cells were serially replated. Data show results from representative experiments. Mean values (± SEM) are shown; *P < .05; ***P < .001.