EPAS1 and nonpapillary renal cell carcinoma: Under a hypoxic state, ccRCC cells overexpress HIF‐related pro‐angiogenesis (HIF‐1α and HIF‐2α) and glycolysis target genes, which in turn stimulate the production of related growth factors such as vascular endothelial growth factor, platelet‐derived growth factor, and other growth factors, leading to increased tumor angiogenesis, which promote tumor proliferation, growth, and metastasis, and affect the prognosis.19