Fig 1: Colocalization of IgG and serum amyloid P–component (SAP).(a–c) Immunofluorescence experiments performed on a renal biopsy sample from a patient diagnosed with membranous-like glomerulopathy with masked IgG kappa deposits shows granular glomerular basement membrane staining for (a) SAP and (b) IgG. (c) There is strong colocalization of SAP and IgG in the glomerular basement membrane deposits. (d–f) Immunofluorescence experiments performed on a renal biopsy sample from a patient with 3 phospholipase A2 receptor– positive membranous glomerulopathies shows (d) negative glomerular basement membrane staining for SAP and (e) positive granular glomerular basement membrane staining for IgG. (f) There is lack of colocalization in this patient with 3 phospholipase A2 receptor–associated membranous glomerulopathies. To optimize viewing of this image, please see the online version of this article at www.kidney-international.org.