The values of Ki-67 positive cells not associated with PIN in p27+/- and p27-/- control (placebo-treated) mice are close, with a lack of statistical difference between them: 1.4 ± 0.3% vs. 1.7 ± 0.8% (p > 0.5), respectively (Table 4). Here, CDKN1B is linked to prostate intraepithelial neoplasia.