The present invention provides modified pore-forming protein toxins (MPPTs), capable of being used to kill cancer cells. The MPPTs according to the present invention comprise a modification of the naturally occurring activation sequence comprising one or more general cleavage sites, each of which is cleavable by general activating agent, or plurality of specific cleavage sites, each of which is cleavable by a specific activating agent. Optional further modifications that allow specific targeting of these molecules are also described. These MPPts may be used to treat cancer.
