WT1 and mesothelioma: The primary goal in distinguishing epithelioid types of mesothelioma involves a staining pattern that is generally not seen in adenocarcinomas; this includes positive staining for pankeratin, calretinin, keratin 5/6, and WT1 (but not necessarily all of these), and negative staining for CEA, CD15, Ber-EP4 Moc-31, TTF-1, and B72.3 (Ordonez, 1998; Cappello and Barnes, 2001; Pass et al., 2008).