IFNs have pleiotropic actions on various innate and adaptive immunity cells, namely activation and differentiation of B cells into plasma cells, increased T-cell proliferation and activation, impaired function of regulatory T-cells, and BAFF upregulation by dendritic cells, all of which contribute to SLE pathogenesis.32,34 This high IFN signature seems to have a major impact on the full range of clinical manifestations in SLE. This evidence concerns the gene IFNA1 and systemic lupus erythematosus.