Wagner et al. have demonstrated that upregulation of WT1 in endothelial cells after coronary artery ligation is dependent on a hypoxia-response element in the promoter [13, 14], and our laboratory showed that, in Ewing sarcoma cell lines, upregulation of WT1 by hypoxia results in increased expression of VEGF [15]. This evidence concerns the gene WT1 and Ewing sarcoma.