CD4 and systemic lupus erythematosus: Despite the lack of DCs to induce Treg cells, Foxp3+CD4+CD25+ T cells have been reported to be elevated in peripheral blood of SLE patients, however their suppressive function seemed to be impaired which was related to high levels of IFNα secreted by antigen presenting cells (APCs) of SLE patients (Yan et al., 2008).