MUC5AC and gastric neoplasm: Although it has been reported that sialylation is increased in gastric tumour tissue compared to normal gastric tissue [20] no signal was detected when mucin purified from either cell lysates or supernatants was probed with Maackia amurensis agglutinin (MAA) or Sambucus nigra agglutinin-I (SNA-I) suggesting that sialylation of the N + 2TR + C protein was not occurring.