Moreover, it is important to emphasize the different transcriptional activity of the two isoforms in VHL-associated renal cell carcinoma; in these cells, HIF-1α has pro-apoptotic features, whereas HIF-2α enhances transcription of genes, thereby promoting tumorigenesis such as VEGF and cyclin D1 [152]. This evidence concerns the gene EPAS1 and renal cell carcinoma.