EPO and neoplasm: GAGE analyses also identified a significant downregulation of the gene set HIF-2α Transcription Network, including Epo, Egln1, Egln3, Igfbp1, and Pfkfb3. To further investigate potential overlap with recently defined HIF-2α-dependent genes in human ccRCC, we used a set of 277 genes that were identified as being inhibited specifically in tumour cells in ccRCC tumorgrafts in mice treated with the HIF-2α inhibitor PT239925,35.