It is notable that IL‐38 injection significantly reduced the levels of inflammatory cytokines IL‐1β, TNF‐α, IL‐6 and IL‐23 in plasma, demonstrating that IL‐38 is able to protect mice from lupus development, and has a negative role in regulating inflammatory cytokines both in vitro and in vivo. Here, IL1B is linked to systemic lupus erythematosus.