Furthermore, a significant inverse correlation was found to exist between lupus disease activity and the level of circulating CD27+CD45RA−γδ Treg cells [67]. In vitro experiment confirmed the ability of lupus CD27+CD45RA−γδ Treg cells to express FoxP3 in a CD27-dependent fashion when the cells were cultured in the presence of TGFβ [67]. Here, TGFB1 is linked to systemic lupus erythematosus.