In a study in 1996, Lindeman and Weidner [15] stained 29 prostate adenocarcinomas, 31 urothelial tumors and 5 poorly differentiated carcinomas of uncertain type (prostatic or urothelial origin) located at the junction of bladder neck and prostate with CK7, CK20, PSA, PAP (Prostatic Acid Phosphatase) and CEA (Carcinoembryonic Antigen). Here, KRT20 is linked to prostate adenocarcinoma.