Benign and prostate cancer tissues were obtained from the radical prostatectomy series at the University of Michigan and from the Rapid Autopsy Program, both part of the University of Michigan Prostate SPORE programs, through appropriate informed consent. Institutional Review Board approval was obtained to procure and analyze the tissues used in this study. Immunohistochemistry was carried out to evaluate SUB1 expression using rabbit polyclonal antibody against SUB1 (Novus Biologicals, Littleton, CO, USA; cat. no. NBP1-82454). Immunohistochemistry was performed using an automated protocol developed for the DISCOVERY XT automated slide staining system (Ventana Medical Systems Inc., Tucson, AZ, USA) using Ultramap anti-rabbit HRP (cat. no. 760-4315; Ventana Medical Systems Inc.) and was detected using ChromoMap DAB (cat. no. 760-159; Ventana Medical Systems Inc.). Hematoxylin II (cat. no. 790-2208; Ventana-Roche, Tucson, AZ, USA) was used as the counterstain. The study pathologist Dr Kunju (PK) evaluated the immunohistochemical staining.