GDF15 and prostate intraepithelial neoplasia: This is consistent with the report from a previous study, in which immunohistochemical staining of tissue microarrays containing over 1600 cores of benign prostate tissues, low- and high-grade prostatic intraepithelial neoplasia, and primary prostate cancer samples showed a progressive increase of GDF15 protein levels from benign tissues to low- and high-grade prostatic intraepithelial neoplasia and to prostate cancer [60].