The expression of Notch1 and Notch3 was virtually undetectable in normal kidneys (Fig. 5A, 5B), but clearly evident in nuclei of podocytes within the glomeruli of patients with LES nephritis or FSGS, as demonstrated by double immunolabeling with the podocyte marker PDX (Fig. 5D, 5F). Here, NOTCH1 is linked to focal segmental glomerulosclerosis.