Given the successful regression/eradication of endogenously-formed gliomas achieved by regulated expression of d/n-ATF5 in mouse brain, we devised a modified cell-penetrating form of this peptide for systemic delivery capable of reaching widely dispersed tumor cells through the advantage of rapid biodistribution, reduced immune response, with the ability to pass through the blood brain barrier into neural cells [4]. The gene discussed is ATF5; the disease is central nervous system cancer.