CXCL13 and pemphigus: It also reduces IL-2 production, driving CXCL13 upregulation in CD8+ T cells through the expansion of Treg cells.278 Moreover, in pemphigus chronic blisters, Treg cells have been shown to increase CXCL13 production in CD4+ T cells by mediating the attenuated stimulation of TGF-β in TLSs.137