In accordance with this pattern of developmental expression, in addition to RCCs, PAX8 consistently stains Műllerian neoplasms and thyroid neoplasms, and, in smaller subsets (~20%), urothelial carcinomas of the renal pelvis, Wolffian duct lesions, and thymic neoplasms [6]. This evidence concerns the gene PAX8 and renal pelvis urothelial carcinoma.