PRKCD and urothelial papilloma: The results by real-time PCR showed that in the RT4 cell line (bladder papilloma), the mRNA expression of PKCα ranked sixth compared with the mRNA expression of other PKC isotypes (PKCδ, PKCι, PKCβ, PKCη vs PKCα: p < 0.01**; PKCζ vs PKCα: not significant).