CLDN18

CLDN18

A gene on chromosome 3q22.3 that encodes claudin-18, an integral membrane protein of the claudin family, the members of which form a physical barrier that prevents solutes and water from passing freely into the interstitial space between epithelial or endothelial cell sheets, and play critical roles in maintaining cell polarity and signal transduction. CLDN18 expression in gastric cells is regulated by the PKC/MAPK/AP-1 (protein kinase C/mitogen-activated protein kinase/activator protein-1)-dependent pathway.

Molecular pathology
CLDN18 is upregulated in ulcerative colitis and seriously overexpressed in infiltrating ductal adenocarcinomas.