Figure 1 Example immunohistochemistry images with the active nuclear factor‐κB (NF‐κB) and interleukin‐8 (IL‐8) antibodies in squamous, Barrett's and adenocarcinoma sections, showing increasing staining across the histological series. Negative controls (no antibody) are shown for the active p65 antibody (adenocarcinoma material) and the IL‐8 antibody (Barrett's metaplasia material). Positive controls are also shown (breast ductal cancer for active p65 and tonsil for IL‐8).