Although previous reports using recombinant protein showed that IL-1β can act as a tumor-suppressing agent in B16F10 and other tumor types51,52, single electroporation of plasmid encoding IL-1β did not exhibit any tumor shrinkage capacity nor long-term survival (Fig. 4c, d and Supplementary Fig. 6a), likely due to lower IL-1β exposure or other parameters originating from different treatment systems used. This evidence concerns the gene IL1B and neoplasm.