According to previous studies, CD25 was a late activation marker of T cells and a characteristic marker of regulatory T (Treg) cells.22 23 No significant differences in percentages of CD8+ Treg cells between the patients with SLE and the HCs (data not shown) indicated that the lower percentages of CD25+ CD8 αβ T cells in the SLE group were not attributed to a decrease in late activation of CD8 αβ T cells. Here, CD8A is linked to systemic lupus erythematosus.