Immunization with lipopolyplexes containing ovalbumin mRNA increased IFN-β levels present in serum six hours after vaccination (A), increased T cell activation, measured as upregulation of CD69 (B), increased IFN-γ secretion by cells from the lymph nodes upon restimulation with OT-I cells (C), and promoted antigen-specific killing of B16-OVA melanoma cells in vitro (D). Vaccination also decreased the number of metastatic tumor nodules in the lungs of mice (E). Vaccination with lipopolyplexes containing mRNA for tumor antigen TRP2 increased IFN-γ production by peripheral blood mononuclear cells (PBMCs), suggesting immune activation (F), and increased the percentage of antigen-specific CD8+ T cells in mice (G). Reprinted from Biomaterials, Vol. 125, Persano et al., “Lipopolyplex potentiates anti-tumor immunity of mRNA-based vaccination,” pg. 81–89, Copyright Elsevier (2017) [97].