In the late ‘90s, the use of mouse xenograft models demonstrated that only CD34+CD38− human AML purified cells (which can be as low as 0.2% of the total leukaemic cells) were able to repopulate non-obese diabetic mice with severe combined immunodeficiency disease (NOD/SCID mice) and transfer AML. Here, CD38 is linked to acute myeloid leukemia.