To test whether Notch signaling regulates NE differentiation in prostate cancer, we utilized the Rosa26-loxP-STOP-loxP-Nicd1-EGFP allele that ectopically expresses the Notch1 intracellular domain (Nicd1) in mice after Cre-mediated recombination, constitutively activating Notch signaling independent of the ligand (44). Here, NOTCH1 is linked to prostate carcinoma.