FOXP3 and systemic lupus erythematosus: Therefore, to further investigate the nature of CD25lowFOXP3+ T cells, we employed a recently developed targeted single-cell RNA-sequencing approach combining mRNA and protein quantification (29), to characterize the FOXP3+ cells within both CD127lowCD25low and CD127lowCD25hi populations from one SLE patient displaying an expanded Treg compartment, as well as two control donors (one type 1 diabetic and one healthy donor).