Interleukin-27 (IL-27) can partially reduce tumor growth in several animal models, including pros-tate cancer. We describe our findings on the effects of IL-27 gene delivery on prostate cancer cells and how sequential therapy with IL-18 enhances the efficacy of IL-27. We applied IL-27 and IL-18 deliv-ery with the goal of reducing prostate tumor growth, first in cell culture and then in an immunocom-petent mouse model. The combination of IL-27 followed by IL-18 (2718) successfully reduced can-cer cell viability, with significant effects found for a particular combination sequence. Interestingly, when we compared the 2718 combination with a single cytokine targeted to IL-6R via an oligo-peptide (27pepL) recently developed by our group, we observed similar efficacy. This efficacy was further enhanced when 27pepL was sequenced with IL-18 (27pepL18) Overall design: We examined total RNA sequencing from tumors on day 26