The Wilms tumour suppressor gene,WT1,is mutated in 10-15% ofWilms tumours and encodes proteins which have diverse cellular functions known to be critical for nephrogenesis,genitourinary development,haematopoiesis and sex-determination.WT1 is a highly conserved,developmentally regulated gene with transcriptional and post-transcriptional functions in a variety of tissues.Work in our laboratory has identified two other transcripts expressed from the human WT1 gene locus.These include an antisense transcript,WT1-AS,and an alternative sense WT1 transcript,AWT1,which are both epigenetically regulated in human kidney,independent of WT1.This means that only a single allele of each is expressed in normal adult kidney.