NKX3-1 and prostate intraepithelial neoplasia: Nkx3.1−/− mice are a model of the early stages of prostate tumorigenesis, exhibiting hyperplasia and dysplasia at 8 weeks of age and progressing to prostatic intraepithelial neoplasia (PIN), a precursor lesion to prostate cancer, later in life [35], [36], [37].