Our recent unpublished in vivo studies with the C57Bl/6 mice have now shown that systemic delivery of a mixture of two plasmids in Tf-PEG-PEI-nanoparticles (pARR2-Probasin-Cre/Tf-PEG-PEI-nanoparticles and floxed pSico-CD44v9shRNA/Tf-PEG-PEI-nanoparticles) can target both localized and metastatic prostate cancer cells. The gene discussed is TF; the disease is prostate cancer.