To enrich for the relative distribution of two less abundant CD4+ T cell subsets: (i) CD127lowCD25hi T cells, predominantly containing the Treg population; and (ii) CD127lowCD25low T cells, containing a subset of non-conventional CD25lowFOXP3+ Tregs previously characterised in autoimmune patients [17], we devised a FACS-sorting strategy to isolate and profile equal numbers of cells from the three defined T cell subsets (Fig. 1a). This evidence concerns the gene CD4 and Autoimmunity.