Mucin 16 is a membrane associated mucin that possesses a single transmembrane domain. MUC5AC Mucin 5AC is a gel-like mucin product of goblet cells. Mucin secretion in the airway may occur via regulated secretion. MUC16 is a transmembrane mucin expressed at the apical surface of uterine epithelia. Effective mucociliary clearance depends on airway hydration, ciliary beating, and the rates of mucin secretion. An important factor is the rate of mucin secretion. Tannin-binding capacity of salivary mucin is directly related to its proline content. MUC16 is a member of the mucin family glycoproteins. It is typically an adenocarcinoma (a cancer that forms glands or secretes mucin). Microscopically, mucoceles appears as granulation tissue surrounding mucin. Such clefts are caused by shrinkage of mucin during tissue fixation and staining. The heavy aggregates of mucin determine a cystic structure. This results in mucin hypersecretion by goblet cells and decreased mucociliary activity. This gene encodes a member of the mucin protein family. Goblet cells are filled with mucin (MUC).