The Dörner's group previously stressed heterogenous CD19 MFI in relationship with CXCR5 expression and subdivided B cell populations according to low, intermediate, and high CD19 expression describing the novel subset CXCR5-CD19lo enriched in SLE in both SWM and DN B cells [16]. This evidence concerns the gene CXCR5 and systemic lupus erythematosus.