CD4 and systemic lupus erythematosus: The superiority of CD4+CD25+CD127low UCB-Tregs is highlighted by their ability to suppress both pathogenic SLE cells and healthy donor Tcon cells, to a similar degree, and thus provides proof that CD4+CD25+CD127low UCB-Tregs are not impacted by the potential Teff resistance, well described as a possible point of failure in using CD4+CD25+CD127low Treg adoptive therapy in SLE (14).