In this study, we used the new guidelines recommended by The Mouse Models of Human Cancers Consortium Prostate Pathology Committee in 2013 for our pathological analyses32 (link). Mouse tissues were fixed and processed as described in our previous study31 (link). Tissue slides were exposed to different first antibodies in PBS with 1% goat serum at 4°C overnight, including 1:500 dilution of anti-human AR (sc-7305, Santa Cruz), 1:500 dilution of anti-mouse/human AR (sc-816, Santa Cruz), 1:250 dilution of anti-p63 (sc-8431, Santa Cruz), 1:3000 dilution of anti Ki67 (NCL-ki67, Novacastra), 1:500 dilution of anti-β-catenin (sc-7199, Santa Cruz), 1:300 dilution of anti-E-cadherin (c20820, Transduction Laboratories), 1:800 dilution of anti-CK5 (PRB-160P, Covance), 1:800 dilution of anti-CK8 (MMS-162P, Covance), 1:200 dilution of anti-synaptophysin (18-0130, Invitrogen), 1:100 dilution of anti-SPP1 (91655, Abcam), and 1:50 dilution of anti-Egr1 (4153, Cell Signaling) antibodies. Slides were then incubated with biotinylated anti-rabbit or anti-mouse secondary antibody (BA-1000 or BA-9200, Vector Laboratories) for 1 h, horseradish peroxidase streptavidin (SA-5004, Vector Laboratories) for 30 min, and then visualized by DAB kit (SK-4100, Vector Laboratories). All samples were subsequently counterstained with 5% (w/v) Harris Hematoxylin.