This gene encodes an integral membrane protein, which belongs to the claudin family.

The protein is a component of tight junction strands and may play a role in internal organ development and function during pre- and postnatal life.

This gene is deleted in Williams-Beuren syndrome, a neurodevelopmental disorder affecting multiple systems.

[5] Claudin 4 can also be used as a marker for distinguishing malignant mesothelioma from lung cancer and uterine serous carcinoma.

[6] As a pancreatic cancer marker in cell-blocks of effusion specimens, it has also been found to have a superior performance to BerEp4 staining.