While the positive controls MUC1 (lane 1), colonic mucus (lane 4), pseudomyxoma peritonei (lanes 7 and 10) [20] reacted with the anti-MUC1, anti-MUC2, anti-MUC5AC and anti-MUC5B antibodies respectively, the negative controls namely the salivary MUC5B (lane 2), tracheal sputum (lane 5), salivary MUC7 (lane 8) and gastric mucus (lane 11) did not react with the anti-MUC1, anti-MUC2, anti-MUC5AC and anti-MUC5B antibodies respectively. This evidence concerns the gene MUC5B and pseudomyxoma peritonei.