WT1 and renal cell carcinoma: Both WT1-positive RCCs were ccRCCs, with an identical pattern of WT1 intratumoral expression, i.e., moderate RCC positive cell density (QS = 2), but strong intensity of WT1 nuclear reactions (IS = 3), yet very difficult clinical presentations (62-year-old male, pT3aG2cN0M0 vs. 58-year-old female, pT1aG1cN0M0).