To facilitate the conversion of the GCN4-TRAIL chimera into a potent anti-tumor agent applicable for cancer therapy, we substituted the yeast GCN4 leucine zipper sequence with several human leucine zipper motifs in which the amino acid residues at the “a” and “d” positions of the coiled-coil heptad repeats of leucine zipper were substituted for Ile (Fig 2). The gene discussed is TNFSF10; the disease is cancer.