These findings also suggest that there is an age-dependent increased differentiation of both RTE Tregs and RTE Tresps via CD31+ memory Tregs/Tresps into CD31− memory Tregs/Tresps in SLE patients which is strongly suppressed by azathioprine or mycophenolate mofetil medication. This evidence concerns the gene PECAM1 and systemic lupus erythematosus.