Samples were stained with H&E, ERG, and PIN-4, and laser capture microdissected (LCM) as previously described (13 (link)). No differences were observed between H&E, ERG, and PIN-4 staining for tissues fixed in formalin versus PAXgene. For c-Myc and MAD automated immunohistochemical staining, 5 μm FFPE sections were baked for 1 hour at 60°C. After cooling to room temperature, antigen retrieval was performed using PT Link (Dako). Staining was with EnVision FLEX High pH kit (Dako, cat# K8000021-2) following the manufacturer's recommendations. Sections were incubated with 300 μL primary antibody (anti-c-Myc, Abcam cat# ab32072, 1:200 dilution; anti-MAD, Sigma-Aldrich cat# HPA001599, 1:1000 dilution) for 60 minutes at room temperature.