HDAC1 and systemic lupus erythematosus: In addition, we demonstrated that the downregulation of transcription factor RFX1 caused the DNA hypomethylation, the increased H3 acetylation, and the decreased H3K9 tri-methylation through the reduced recruitment of HDAC1, SUV39H1, and DNMT1 to the promoter region of IL17A in SLE CD4+ T cells.