Autoantibody secreting cells are mainly derived from acN (CD19hi IgD + CD27–) and DN2 (IgD– CD27– CXCR5– CD11c+) B cells that are enriched in the 9G4 idiotope (VH4-34 immunoglobulin gene rearrangement) and are known to expand in active SLE patients [7,8]. The gene discussed is CD27; the disease is systemic lupus erythematosus.