Test Details: Immunohistochemical testing is carried out on biopsy/resected tissue specimen. This testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody. Calretinin is an intracellular neuron-specific calcium-binding vitamin D-dependent protein expressed in various epithelial, mesenchymal, and central and peripheral neurogenic tissue types. Calretinin is an important mesothelioma marker and useful marker to differentiate malignant mesothelioma from adenocarcinoma. It is used in sex cord stromal tumours also.