Recombinant therapeutic cytokines (“therakines”) for the treatment of cancer are provided. The recombinant therakines include a truncated region of MDA-7/TL-24 (“M4”) not normally found in nature that has anti-cancer activity and a secretory signal which causes secretion of the therakine from plasmid/virus transduced normal and cancer cells and interaction of the therakine to MDA-7/IL-24 receptors on adjacent, neighboring and distant cancer cells. Therakine interaction results in bystander killing of the target cancer cell as well as adjacent, neighboring and distant cancer cells.