BCR and chronic myelogenous leukemia, BCR-ABL1 positive: The crucial role of HIF1α in promoting maintenance of CML LSCs was also validated in a BCR-ABL transgenic mouse model, where HIF1α conditional deletion resulted in impaired LSCs propagation caused by delayed proliferation and induction of apoptosis via expression of p16Ink4a, p19Arf and p53 (86).