WT1 and malignant mesothelioma: A recent study summarizing the mesothelioma positive rates indicated that the SKM9-2 antigen (sialylated HEG1) was more useful than conventional markers (calretinin, WT-1, and podoplanin) in detecting the major histological forms of malignant mesothelioma (epithelioid-type) markers: SKM9-2, 97%; WT-1, 81%; podoplanin, 84%; calretinin, 92% (11).