IL1B and polyarticular arthritis: However, whilst breeding of Dnase2−/−Ifnar1−/− mice on a TNFα or IL-6 null background, or treatment with a monoclonal antibody against the IL-1 receptor, ameliorated the murine polyarthritis phenotype22, the use of biologics targeting TNFα and IL-1 signaling has shown minimal clinical efficacy in this patient.