Importantly, our data clearly show, for the first time, that effective killing of MLL-AF9 AML cells by daunorubicin in vivo is dependent on expression of Puma and Noxa, as the AMLs lacking these BH3-only genes were more refractory to treatment (compare Figures 5c and d with a). The gene discussed is PMAIP1; the disease is acute myeloid leukemia.