TUNEL staining and quantification of TUNEL-positive cells in peripheral area of glomeruli, as well as the double-staining of activated Caspase 3 and podocyte cytoplasm marker podocin, showed more apoptotic podocytes in FSGS patients compared to MCD patients (Fig. 1E–G). Here, CASP3 is linked to focal segmental glomerulosclerosis.