Description: The gene encoding Wilms' Tumor Protein is a suppressor gene located on chromosome 11p13. WT1 has been identified in proliferative mesothelial cells, malignant mesothelioma, ovarian cystadeno-carcinoma, gonadoblastoma, nephro-blastoma and desmoplastic small round cell tumor. The WT1 gene is normally expressed in fetal kidney and mesothelium, and its expression has been suggested as a marker for Wilms' tumor and mesothelioma. Lung adenocarcinoma is rarely positive with this antibody.