Downregulation of HLA and PML protein expression in prostate adenocarcinoma. Representative set of paired serial sections from a formalin-fixed, paraffin-embedded prostatectomy sample. Left, H&E stained section (400x). Right, double stained section, with HC10 primary antibody staining in brown and with PG-M3 primary antibody staining in purple (400x). Sections (A) and (B) show a prostate intraepithelial neoplastic (PIN) change, demonstrating expression of both HLA and PML. Sections (C) and (D) show an intermediate grade prostate adenocarcinoma, demonstrating partial simultaneous expression of HLA and PML on the same cells. Sections (E) and (F) show a high-grade prostate adenocarcinoma, demonstrating simultaneous loss of expression of HLA and PML on tumor cells. Arrows mark the positively stained endothelial cells in a blood vessel.