A growing body of evidence demonstrate that XAF1 activates caspases and increases tumor cell response to various apoptotic stresses, including γ-irradiation, fluorouracil (5-FU), H2O2, and growth factor withdrawal, and regulates autophagic cell death, tumor angiogenesis, and G2/M checkpoint of the cell cycle11–13. The gene discussed is XAF1; the disease is neoplasm.