{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Claudin-4 belongs to the tight-junction-associated protein group. The expression of Claudin-4 is found in most epithelial cells but not in mesothelial cells. \n Detection of Claudin-4 via IHC allows distinguishing Adenocarcinoma from malignant Mesothelioma in tissue samples. In malignant effusions, Claudin-4 detection effectively identifies Adenocarcinoma from malignant Mesothelioma with high sensitivity and specificity. Another study showed that Claudin-4 detection is an independent positive prognostic factor for Gastric Carcinoma which restricts the migration of gastric cancer cells. Claudin-4 overexpression in gastric cancer cells is associated with epigenetic derepression and contributes to the suppression of gastric cancer progression and positive prognosis of the patient. On the other hand, Claudin-4 expression is downregulated in epithelial malignancies and in precancerous lesions. In addition, Claudin-4 plays an important role in tumor cell invasion and metastasis. Claudin-4 is a highly specific and sensitive marker to differentiate epithelioid mesotheliomas from metastatic carcinomas."}]}]}