Then by Set1-siRNA, we found reduced Set1 abundance alleviated H3K4me3 and augment the DNA methylation and DNMT3a enrichments within the CREMα promoter region of SLE CD4+ T cells, thus down-modulating the CREMα level, and augmenting IL-2 production and blocking IL-17A secretion. The gene discussed is SETD1A; the disease is systemic lupus erythematosus.