To investigate the ability of OTS167 to inhibit FLT3 mutant stem cell function, primary cells from two newly diagnosed FLT3 mutant AML patients were tested in colony-forming cell assays in the presence of 1 or 4 nM OTS167, 1 or 4 nM gilteritinib or a combination of equal doses of both drugs. This evidence concerns the gene FLT3 and acute myeloid leukemia.