TNF and systemic lupus erythematosus: Addition of CD4+CD25+CD127low UCB-Tregs to the proliferating SLE-PBMCs significantly decreased the secreted TNF-α levels to 5,071 ± 97 pg/ml at 3 days (p < 0.0001) and 5,564 ± 50 pg/ml at 7 days (p < 0.0001, Figure 2D).