Therefore, our findings, regarding intratumoral WT1 nuclear staining of endothelial cells (2 arteries and 1 vein), in otherwise WT1-negative aRCCs, may be reflective of molecular vascular adaptations to ischemia in the RCC microenvironment or the proangiogenic function of WT1 in cancers. This evidence concerns the gene WT1 and renal cell carcinoma.