CALB2 and malignant mesothelioma: In addition, calretinin expression evaluated by immunohistochemistry (IHC) in the three most frequent types of malignant mesothelioma separately present data that diverge from 18 to 100% positivity in sarcomatoid malignant mesothelioma, and 8 to 100% in biphasic malignant mesothelioma45.