Stabilizer of the mucous gel overlying the gastrointestinal mucosa that provides a physical barrier against various noxious agents. May inhibit the growth of calcium oxalate crystals in urine.

Found in stomach, with highest levels in the upper gastric mucosal cells (at protein level). Detected in goblet cells of the small and large intestine and rectum, small submucosal glands in the esophagus, mucous acini of the sublingual gland, submucosal glands of the trachea, and epithelial cells lining the exocrine pancreatic ducts but not in the remainder of the pancreas (at protein level). Scattered expression is detected in the epithelial cells of the gallbladder and submucosal glands of the vagina, and weak expression is observed in the bronchial goblet cells of the pseudostratified epithelia in the respiratory system (at protein level). Detected in urine (at protein level). Strongly expressed in breast cancer but at low levels in normal mammary tissue. It is regulated by estrogen in MCF-7 cells. Strong expression found in normal gastric mucosa and in the regenerative tissues surrounding ulcerous lesions of gastrointestinal tract, but lower expression found in gastric cancer (at protein level).

Contains 1 P-type (trefoil) domain.

Secreted.