NPHS2 and glomerulosclerosis: This was associated with reduced glomerular expression of the homeostatic podocyte marker podocin and increased accumulation of the extracellular matrix protein fibronectin, as shown by fluorescent immunohistochemical staining (Supplemental Figure 2H) and by immunoblot analysis of isolated glomeruli (Supplemental Figure 2J), consistent with glomerular sclerosis.