Uroplakin II [BC21] and Uroplakin III [BC17] are highly specific antibodies that may be useful in identifying tumors of urothelial origin. With the exception of bladder and ureter, staining was highly specific in various normal and neoplastic tissues in an in-house study. Both antibodies exhibited increased staining sensitivity when compared to Uroplakin III [AU1] in cases of urothelial carcinoma of the bladder. Uroplakin II + Uroplakin III antibody may be a specific and sensitive antibody cocktail for urothelial carcinoma and in discriminating bladder cancer from renal and prostate carcinomas. PATENT PENDING.