We studied mucin production in the unsectioned colon, demonstrating that ACFs producing sulphomucins (like the normal distal rat colon) were progressively reduced when ACF multiplicity increased, whereas ACFs containing sialomucins (correlated with an increased risk of colon cancer) or both sulphomucins and sialomucins increased with crypt multiplicity. The gene discussed is MUC5AC; the disease is malignant colon neoplasm.