NOTCH1 and prostate intraepithelial neoplasia: Cleaved Notch-1: IHC analysis for cleaved Notch-1 (activated Notch-1) expression revealed that its expression was markedly increased in all stages of PCa, especially in the more aggressive stages; however, there was no difference between low-grade and high-grade PIN stage expression, and the difference in cleaved Notch-1 expression was almost similar between WD, MD, and PD stages.