MSLN and malignant epithelioid mesothelioma: Epithelioid mesothelioma showed significantly higher mesothelin expression (81% with 5B2 and 84% with MN-1) than sarcomatoid (20% with 5B2 and 20% with MN-1) and biphasic (65% with 5B2 and 65% with MN-1) histotypes with both antibodies.