Nevertheless, given that even in SLE patients FOXP3+ cells represent at most 30–50% of the heterogeneous CD127lowCD25low T-cell population, it is critical to identify appropriate surface markers to unequivocally demonstrate the suppressive capacity of the different CD25lowFOXP3+ T cell subsets, particularly within the HELIOS− fraction. Here, FOXP3 is linked to systemic lupus erythematosus.