IFNA1 and systemic lupus erythematosus: For example, in SLE, a systemic autoimmune disease, an elevated peripheral IFN signature consistent with induction of type I IFN characterises the disease1, and in SLE patients, blood monocytes show an especially prominent type I IFN response as do pDCs1, two cell types in which we have shown a role for MNDA in controlling IFNα production.