Immunohistochemical detection of ZIP1 transporter protein in malignant and nonmalignant loci of a representative prostate cancer tissue section. (A) BPH, magnification is 1000×, bar = 10 μm. (B) Normal, magnification is 400×, bar = 25 μm. (C) PIN, magnification is 400×, bars = 25 μm. (D) Adenocarcinoma, magnification 400×, bar = 10 μm Note the immuno-positivity of the plasma membrane of BPH and normal glands. The malignant and PIN loci show no detectable ZIP1 so that the plasma membrane of these cells is not visible.