Immunohistochemical Analysis of GLS1 in Prostate Tissues. (A) Benign central zone of the prostate with no glutaminase (GLS1) staining, 40× magnification. (B) Grade Group 1 Prostate Adenocarcinoma showing no staining with GLS1, 40× magnification. (C) Grade Group 3 Prostate Adenocarcinoma showing no GLS1 expression, 40× magnification. (D) Benign Central zone of the prostate with faint but diffuse granular cytoplasmic staining (low expression) with GLS1, 40× magnification. (E) Grade Group 2 Prostate Adenocarcinoma showing faint but diffuse granular cytoplasmic staining (low expression) with GLS1, 40× magnification. (F) Grade Group 5 prostate adenocarcinoma showing moderate but focal granular cytoplasmic staining (low expression) with GLS1, 40× magnification. (G) Grade Group 1 Prostate Adenocarcinoma showing strong and diffuse granular cytoplasmic staining (high expression) with GLS1, 40×. (H) Grade Group 3 Prostate Adenocarcinoma showing variably strong but diffuse cytoplasmic granular staining (high expression) with GLS1, 40×. (I) Grade Group 5 Prostate Adenocarcinoma showing single infiltrating tumor cells and poorly formed glands with strong, diffuse granular cytoplasmic staining (high expression) with GLS1, 40×.