We first quantified the relative proportions of Naïve (IgD + CD27−), unswitched memory (USWM: IgD + CD27+), switched memory (SWM: IgD-CD27+), double negative (DN: IgD-CD27−) B cell subsets in SLE and HD (Fig. 1A). This evidence concerns the gene CD27 and systemic lupus erythematosus.