Studies on lupus CD4+ T cells have shown that UV-B radiation inhibits SIRT1-mRNA and protein expression by activating AhR and suppressing DNMT1 activity in CD4+ T cells by binding upstream of the SIRT1 promoter translation initiation site, thus mitigating the progression of the pathological process (128). This evidence concerns the gene AHR and systemic lupus erythematosus.