Immunohistochemical analysis of Nrf2 and Keap1 in pancreatic tissues. A and B, Pancreatic cancer tissue showing strong and weak Nrf2 levels, respectively. E and F, Pancreatic cancer tissue showing Keap1 expression. C and G, Pancreatic cancer tissue showing absence of detectable Nrf2 and Keap1, respectively. D and H, Benign pancreatic tissue showing Nrf2 expression in ductal cells and acinar cells (D) and absence of Keap1 in ductal cells, with positive islet cells (H). Scale bars = 50 μm.