BCR and leukemia: From healthy control (Tal1-tTA+) and CML-affected (Tal1-tTA+TRE-BCR-ABL1+) littermates, we isolated the following cell subsets: the immature KLS+ (cKit+Lineage−Sca-1+) population, which includes normal HSCs and CML stem cells (also known as leukaemia-initiating cells (LICs)), the committed progenitor KLS− (cKit+Lineage−Sca-1−) population and the mature Lin+ (Lineage+) population.