MYC and prostate intraepithelial neoplasia: Morphologically, the gross phenotypes of the whole-mount prostate lobes from Tg2;Hi-Myc mice were indistinguishable from those of the Hi-Myc mice, both of which manifested clear-cut hyperplasia (i.e., PIN or prostate intraepithelial neoplasia) and tumor growth (Figure 5B).