Co-culture with CD4+CD25+CD127low UCB-Tregs also decreased the percentage of CD56+ NK cells in the SLE-PBMC population, implicated in excessive IFN-γ production in patients with active SLE (39), where elevated levels of IFN-γ have been shown to be associated with nephrotic syndrome (40). Here, CD4 is linked to systemic lupus erythematosus.