Ectopic podocyte Notch activation in mice results in podocyte apoptosis, dedifferentiation, and both diffuse mesangial sclerosis and FSGS phenotypes,27, 28 which are also associated with mutations in WT1.5, 7 Following Wt1 deletion in this model, we show upregulation of several Notch components, including Notch1 and its transcriptional target gene, Nrarp,35 as well as Notch bHLH transcription factors. This evidence concerns the gene WT1 and focal segmental glomerulosclerosis.