Inlupus-prone NZB*NZW F1 female mice, IFN-α or IFN-γ act synergistically withoestrogen to increase the expression of oestrogen (E2)- and IFN-responsive genes.23 Both IFN-inducible genes and oestrogens have a pathogenetic role in SLE.23 The IRF5 gene, which is associated with increased risk of SLEdevelopment, is upregulated in lupus-prone mice both in steady conditionsand following oestrogen treatment and regulates type 1 IFN expression.24 This evidence concerns the gene IFNG and systemic lupus erythematosus.