CD99 and acute myeloid leukemia: They separated the cells of three distinct stages of AML evolution, pre-leukemic haematopoietic stem cells (pHSCs; CD34+CD38negCD99negTIM3neg), leukemic stem cell (LSCs; CD34+CD38negCD99+TIM3+), and leukemic blasts (Blasts; CD99+TIM3+CD45midSSChigh), characterized their transcriptome, and analysed their coding gene expression patterns21.