Interleukin-1 family member 7 (IL1F7b) ,a member of the IL-1 family, is aslo known as interleukin-37, interleukin-1 homolog 4 (IL-1H4), interleukin-1 zeta (IL-1 zeta) and interleukin-1-related protein, which can interact with SMAD3 and bind to IL18R1, but not to IL1R1, with lower affinity than IL18. IL1F7b is a suppressor of innate inflammatory and immune responses involved in curbing excessive inflammation. This function requires SMAD3. Therefore,IL1F7b can suppress, or reduce, proinflammatory cytokine production, including IL1A and IL6, as well as CCL12, CSF1, CSF2, CXCL13, IL1B, IL23A and IL1RN, but spare anti-inflammatory cytokines. Furthermore,IL1F7b can also inhibit dendritic cell activation.