We also confirmed that SLE patients carry more CD25- FOXP3+ CD4+ (CD25- Tregs) than HCs, and found that while the CD25+ conventional Tregs showed variable levels of suppression, the CD25- Tregs were uniformly non-suppressive (and, therefore, are not functionally speaking "Treg"). Here, FOXP3 is linked to systemic lupus erythematosus.