Notably, inactivation of Notch1 in Ptenpc−/− tumours induced a strong inhibition of tumour growth compared with age-matched Ptenpc−/− littermates as measured by decreased number of glands affected by high-grade prostatic intraepithelial neoplasia and invasive PCa (Fig. 1e,f and Supplementary Fig. 1f). Here, NOTCH1 is linked to prostate intraepithelial neoplasia.