Using this nanoparticle delivery system in combination with codon-usage-optimized FAS cDNA, we determined that tumor-selective lipid-nanoparticle-FAS-cDNA-targeted delivery is sufficient to restore FAS expression to suppress metastatic human colon tumor xenograft growth in vivo in the absence of immune cells and thereby in the absence of membrane-bound FASL. The gene discussed is FAS; the disease is neoplasm.