CD4 and systemic lupus erythematosus: Although the markers used to evaluate CD4+Foxp3+ T cell subsets were variable among previous studies, resulting in difficulty in comparing the findings described in individual reports, the CD4+Foxp3+ T cell subsets reported to be increased in SLE patients included Foxp3lowCD45RA+CD25low cells (fraction I) [36], Helios+ T cells [40, 41], CD161+ T cells [42], and IL-17-producing T cells [39], which were consistent with the unique tTreg subset identified in this study.