UPK2 and posterior cortical atrophy: Nevertheless, they found that urothelial carcinoma (UCC)-associated proteins (e.g., UPK1A, UPK1B, UPK2, UPK3B) were highly enriched in BCa exosomes when compared to PCa exosomes, but the four proteins showed no specific expression between ureter and bladder urine of BCa or between BCa-only and concomitant BCa + PCa.