VEGFA and nonpapillary renal cell carcinoma: Loss of the VHL gene leads to the upregulation of hypoxia inducible factor (HIF) and resultant overexpression of hypoxia-inducible genes, such as vascular endothelial growth factor (VEGF), platelet-derived growth factor-β (PDGF-β), and transforming growth factor-α (TGF-α) (VHL-HIF-VEGF axis), which are involved in tumorigenesis and the progression of ccRCC [4].