The percentages of RTE Tregs/Tresps, MN Tregs/Tresps, CD31+ memory Tregs/Tresps, and CD31− memory Tregs/Tresps were estimated within the total CD4+ T-helper cell pool in both healthy volunteers (black diamond) and SLE patients (red diamond). This evidence concerns the gene PECAM1 and systemic lupus erythematosus.