HIF-2α, at least in some cancers, has a greater oncogenic capacity than HIF-1α and its overexpression (and that of HIF-1α) correlates with poor patient outcome in colorectal carcinoma, melanoma, ovarian cancer and hepatocellular carcinoma, [8,30,44-46] possibly by promoting Myc activity, and radio- and chemo-resistance through indirect suppression of p53 activity [8,44-46]. Here, EPAS1 is linked to cancer.