Insulin stimulates proliferation of primary human AML cells for at least a subset of patients,11 and the PI3K-Akt-mTOR pathway is one of several pathways that may be activated by the insulin receptor.7,8 We observed that insulin increased the phosphorylation of several members of this signaling network, but insulin responsiveness and the effect of pathway inhibitors varied across patients. The gene discussed is INSR; the disease is acute myeloid leukemia.