FIGURE 1. Gel mobility shift assay for NF-κB binding activity in esophageal biopsy tissue. A, Expression of NF-κB in nuclear extracts from esophageal tumor tissue, showing a strong band of NF-κB activation in tumor tissues (T) compared with non tumor tissues (C) from the same patient. B, Supershift assay was also performed on the same nuclear extracts using 0.5 μL of rabbit antisera to p50, lane 2, RelA, lane 3, and c-Rel, lane 4 antibodies in esophageal tumor tissue. Competition assay for NF-κB was also performed using molar excess (1 μL) of cold probe, lane 5. Each experiment was repeated 3 times and a representative gel is shown.