Interleukin-18 (IL-18) is a pro-inflammatory cytokine that modulates innate and adaptive immune responses. Decoy-resistant IL-18, DR-18, from Simcha Therapeutics Inc., is an engineered IL-18 cytokine able to interact with the IL-18 receptor but resistant to IL-18-binding protein (IL18BP), which is a negative regulator of IL-18 signaling, thus overcoming the antitumoral efficacy limitation seen with recombinant IL-18.