Concerning B cells, we used a simple flow cytometry gating strategy and quantified 4 relevant B cell populations previously described as being dysregulated subsets in active SLE patients: CD19hi CD27– (“atypical naive” B cells, see below), CD19+ CD27+ (memory B cells), CD19+ CD27– (conventional resting naive B cells), and CD19lo CD27hi (plasmablasts) (Fig. 1A) [7,8]. This evidence concerns the gene CD27 and systemic lupus erythematosus.