Then, we assayed the expression of CD44v6 in progenitor cells (CD34+, CD117+ and HLA‐DR+) of AML patients with FLT3 and healthy donors by flow cytometry, and found that CD44v6 was highly expressed in AML patients but not in healthy donors (Figure 1D,E). This evidence concerns the gene FLT3 and acute myeloid leukemia.