A significant increase in cellular proliferation was observed in high-grade PIN lesions of PtenloxP/loxP:Osr1-Cre mice in comparison to normal prostate tissues of PtenLoxP/+:Osr1-Cre and PtenloxP/loxP mice (Fig. 4A to 4I). The gene discussed is OSR1; the disease is prostate intraepithelial neoplasia.