To determine the expression of FLT3/ITD in AML stem cells, highly purified (purity >95 %) CD34+/CD38−/CD123+ and CD34+/CD38−/CD123− cells were examined for FLT3/ITD mutation in seven patients with FLT3/ITD-positive AML as demonstrated in Fig. 4. Here, FLT3 is linked to acute myeloid leukemia.