Interestingly, for the RCC-patient-derived xenograft model, investigators analyzed a total of 16 resected RCC specimens for WT1 antigen expression, using the 6F-H2 monoclonal antibody, and found WT1 positivity (not mentioned if nuclear or cytoplasmic) in 13 (81.25%) cases [42], the highest reported so far. Here, WT1 is linked to renal cell carcinoma.