EPAS1 and nonpapillary renal cell carcinoma: The associations between HIF-2α and angiogenesis form the basis of current targeted therapy strategies for ccRCC patients, for example, sunitinib, which targets vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF), both of which are important downstream targets of HIF-2α [52, 53].