Total β-catenin expression in oesophageal SCCs. β-catenin levels were assessed by a modified RIA. β-catenin expression (blue) does not differ significantly between the five moderately differentiated oesophageal SCC cell lines (F(4,42) = 1.09; p = 0.37). However, it should be noted that WHCO3 and SNO display slightly lower levels of the protein than the other three cell lines. The control (yellow) indicates non-specific binding of 125I-protein A is statistically negligible (F(1,42) = 60.69; p < 0.001) and no interaction occurred between the experimental and control groups (F(4,42) = 0.79; p = 0.54).