Wilms tumor protein is a transcription factor that contains four zinc-finger motifs at the C-terminus and a proline/glutamine-rich DNA-binding domain at the N-terminus. It has an essential role in the normal development of the urogenital system, and it is mutated in a subset of patients with Wilms' tumor, the gene's namesake. Multiple transcript variants, resulting from alternative splicing at two coding exons, have been well characterized. There is also evidence for the use of non-AUG (CUG) translation initiation site upstream of, and in-frame with the first AUG, leading to additional isoforms.WT1 mRNA undergoes RNA editing in human and rat, and that this process is tissue-restricted and developmentally regulated.The WT1 protein has been found to bind a host of cellular factors, e.g. p53, a known tumor suppressor.