In conclusion, in two FLT3‐ITD positive AML cell lines as well as in FLT3‐ITD positive patient‐derived leukemia cells, the multikinase inhibitor sorafenib synergistically increases the cytotoxicity achieved with nucleoside analogs and the DNA alkylating agent Bu, but not in cells that only have wild‐type FLT3. Here, FLT3 is linked to leukemia.