WT1 and nonpapillary renal cell carcinoma: The same author, in a later investigation, evaluated a different, wider panel of IHC markers, again including WT1 (6F-H2 monoclonal antibody), in 48 mesotheliomas (40 epithelioid/8 sarcomatoid), and the same number of RCCs (24 clear cell, 12 chromophobe, 8 papillary and 4 sarcomatoid), and found WT1 nuclear expression in >50% tumor cells in a single case of conventional ccRCC that had metastasized to the lung (4% of the ccRCC cases evaluated) [55].