Incubation of peripheral blood mononuclear cells (PBMCs) with the human AML cell line, ML-2, for 5 hours at 37°C induced: 1) CD16 down-regulation on NK cells; 2) apoptosis of NK cells as indicated by an increased frequency of Annexin-V+ NK cells as compared to the PBMCs incubated without the leukemic cell line and 3) depletion of NK cells as shown by a reduction in their number as compared to that in PBMCs incubated without the leukemia cell line. The gene discussed is ANXA5; the disease is leukemia.