HIF1A and nonpapillary renal cell carcinoma: Considering the important role of von Hippel–Lindau (VHL)/hypoxia-inducible factor 1 subunit alpha (HIF1α) pathway in stimulating angiogenesis, inducing tumor cell proliferation, invasion, and metastasis in ccRCC, it is possible that polymorphic variations in the Von Hippel-Lindau gene (VHL) may have an influence on the susceptibility or prediction of ccRCC [6].