Leukemic cells from acute myeloid leukemia patients can express high levels of the bcl-2 gene (89) which suppresses apoptosis (90), and in these leukemic cells GM-CSF upregulated expression of bcl-2 (89). It has been suggested that reducing the level of viability-inducing cytokines or the responsiveness of cancer cells to these cytokines may be clinically useful in cancer therapy (33, 81, 86).