Immunohistochemistry was performed as described previously 43 (link). Bones were decalcified in 10% EDTA for 2 weeks before processing. Tumors or prostate tissues were fixed in 4% PFA, transferred to 70% ethanol, and trimmed before standard histological processing, sectioning, and H&E staining performed by Histoserv Inc. (Germantown, MD). H&E and IHC slides were scanned using a Carl Zeiss AxioScan Z1 microscope with a 20X/NA 0.8 plan apochromat objective (Zeiss, Germany). The scale bars in the figures indicated the power of magnification at which the images were captured from the virtual microscope slides.