Germline loss-of-function of Nkx3.1 in mutant mice results in pre-malignant lesions resembling prostatic intraepithelial neoplasia (PIN), a known precursor of prostate cancer, and shares molecular features conserved with indolent prostate cancer in humans (Bhatia-Gaur et al., 1999; Irshad et al., 2013; Kim et al., 2002a). Here, NKX3-1 is linked to prostate intraepithelial neoplasia.