IFNG and systemic lupus erythematosus: ATO treatment was effective in reducing the mRNA and protein expression levels of IFN-γ in the mice splenocytes and human SLE PBMCs, which was accompanied by a reduction in histone H4 and H3 acetylation in the IFN-γ promoter and decreased combination of RNA polymerase II to the IFN-γ promoter.