Together, these studies indicate that exogenous agents can induce lupus flares by decreasing CD4+ T cell DNA methylation levels through mechanisms including decreasing Dnmt1 activity, either by inhibiting its enzymatic activity or decreasing Dnmt1 levels through effects on signaling pathways, or by decreasing the bioavailability of dietary methyl donors. Here, DNMT1 is linked to systemic lupus erythematosus.