Detectable mucin is often present in many disease states. Increased mucin production is indicative of certain adenocarcinomas, including cancers of the pancreas, lung, breast, ovary, and colon. Demonstrating mucin can also help differentiate between adenocarcinomas and squamous-cell carcinomas.
Mucins can be overexpressed in lung diseases such as asthma, bronchitis, chronic obstructive pulmonary disease (COPD), or cystic fibrosis. Staining acid mucins is also helpful in diagnosing diseases associated with the gastrointestinal (GI) tract, such as Barrett's esophagus.