PNP and neoplasm: In this report, we applied L. monocytogenes-mediated protein- and DNA-delivery strategies to introduce the prodrug-drug converting enzymes, purine nucleoside phosphorylase (PNP) and a fusion protein consisting of yeast cytosine deaminase and uracil phosphoribosyl transferase (FCU1) into tumor cells and compared the efficiency of the tumor cell inhibition by these two approaches in several tumor cell lines.