Detection of these rare AML LCSs (approximately 1 per 1 × 106 leukemic blasts) involved fluorescence-activated cell sorting (FACS) of the lymphoid-primed multipotent progenitors like CD34+CD38−CD90−CD45RA+ expressing cells and subsequent proof of identity by their ability to engraft in xenotransplantation assays [108]. Here, CD34 is linked to acute myeloid leukemia.