CXCL13 and lobular neoplasia: To determine whether the expression of CXCL13 is upregulated in the renal tissue of LN patients, we detected the level of CXCL13 in paraffin-embedded kidney tissues from normal and MRL/lpr by immunohistochemisty and immunofluorescent (CXCL13 and collagen 4) staining.