For example, immunohistochemical Napsin A positivity was found in 0%–52% of clear cell renal cell carcinomas [6, 13–22], 72%–97% of papillary renal cell carcinomas [6, 13, 14, 16–18, 20–22], 0%–48% of thyroid tumors [10, 11, 16, 18, 19, 23, 24], 69%–100% of clear cell carcinomas of the ovary [7, 19, 25–32] and 0%–9% of cholangiocarcinomas [12, 19, 33, 34]. Here, NAPSA is linked to papillary renal cell carcinoma.