STAT5B and acute myeloid leukemia: To investigate the elevated susceptibility of FLT3 wild-type SKM-1 compared to FLT3-mutated MOLM-13 cells to AC-4-130, cell viability was determined in AML cells grown in the presence of bone marrow stroma secreting granulocyte and macrophage colony-stimulating factors (G-CSF, GM-CSF, M-CSF), and other cytokines thereby inducing STAT5 signaling.