Figure 2: Peripheral-type benzodiazepine receptor (PBR) protein expression by immunohistochemistry (magnification ×200). DAB stain (brown colour) depicts a significant increase in PBR expression in carcinogenic and non-carcinogenic (benign) tumours. Arrows indicate areas of higher expression. In the graph each bar shows the mean±standard deviation of 25 samples, represented as IOD. ***P<0.001 compared to sham control.