The apoptotic pathways by which MDA-7/IL-24 kills tumor cells remain to be fully understood; however, current evidence suggests an inherently high degree of complexity and an involvement of proteins important for the onset of growth inhibition and apoptosis, including Bcl-XL, Bcl-2 and Bax (3,4,14,17,23–25). The gene discussed is IL24; the disease is neoplasm.