NRARP and focal segmental glomerulosclerosis: 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.