Caveolin-1, an integral plasma membrane protein located on human chromosome 7q31.1, is a member of the highly conserved 20-25kd Caveolin family that are the principal protein components of caveolae. Caveolae are flask-shaped invaginations of the plasma membrane that regulate molecular processes such as signal transduction and cell adhesion. It is expressed in terminally differentiated mesenchymal cells, including fibroblasts, adipocytes, endothelial cells, smooth and striated muscle cells, type I pneumocytes and epithelial cells.

Caveolin-1 was suggested as a useful marker for differentiating epithelioid mesothelioma from lung adenocarcinoma. While antibodies such as Calretinin, D2-40, Wilms’ tumor-1 (WT1), thrombomodulin and mesothelin are well-known markers for mesothelioma, the utility of these antibodies are limited due to their low specificity. Caveolin-1 demonstrated 100% sensitivity and 92.5% specificity in differentiating epithelioid mesothelioma from lung adenocarcinoma. Inclusion of Caveolin-1 into an immunohistochemical panel may aid in the differential diagnosis of epithelioid mesothelioma.