Embodiments are directed to: (i) neutrophil secreted factors that have thecapacityto kill a broad range of cancer cells without affecting the viability of non-cancer cells. Twoneutrophil killing factors have been identified by the inventors: (1)eosinophil cationic protein (ECP)and (2) neutrophil elastase (ELANE); or (ii) therapeutic compositions thatinclude CD95degrading polypeptide components and methods of treating cancer with the same.