Moreover, while in zebrafish AP-2β loss did not result in distal nephron defects, we find that in mice AP-2β is critical for DCT formation and even loss of a single AP-2β allele leads to progressive DCT defects and impairment of renal function with aging as well as to glomerulosclerosis (Fig. 9). The gene discussed is TFAP2B; the disease is glomerulosclerosis.