Since 85% of patients with AML express CD117 on quiescent stem-like cells and proliferating stem/progenitor-like cells, cell-deleting immunotherapies that target CD117 may be a solution to eliminate AML with limited toxicity.32 33 First, we asked whether the level of CD117 on AML affects the CD117×CD3 BTCE-mediated killing of AML and selected four primary AML samples with various expression levels of CD117 (online supplemental figure 6A). This evidence concerns the gene KIT and acute myeloid leukemia.