The abnormal suppressive function of Treg cells in SLE patients may be due to the resistance of SLE-associated effector T cells toward Treg-mediated suppression, or the indirect blockade of Treg cell effectiveness by antigen-presenting cells [26], [27] This scenario provides a rational explanation for the increase in peripheral blood CD45RA+FoxP3low T cells, which correlated with the quantity of CD4+CD25+FoxP3+ Treg in active lupus, and may indicate a positive feedback response to the resistant/blockade effect on Treg cell suppression. Here, CD4 is linked to systemic lupus erythematosus.