Although it is debatable whether its level on B cells is reduced [64] or increased [62, 65], CXCR4-expressing B cells are found to be accumulated in the renal biopsy samples of patients with LN [65], suggesting involvement of CXCL12/CXCR4 in the kidney of patients with LN. Here, CXCL12 is linked to lobular neoplasia.