The decrease in cell viability was ascribed to apoptosis as demonstrated by anti-annexin V antibody and propidium iodide (PI) staining (Figures 1D and 1E), strongly suggesting that sTRAIL and FeSOD synergistically induced apoptosis in the TRAIL-resistant K562 and HL-60 tumor cells. The gene discussed is ANXA5; the disease is neoplasm.