VHL and nonpapillary renal cell carcinoma: Indeed, a very frequent mutation of the tumour suppressor gene VHL in ccRCC (>80% of cases) dysregulates hypoxia-inducing factor (HIF) inducing overexpression of vascular endothelial growth factor A (VEGF-A) and platelet-derived growth factor (PDGF) leading to tumour growth [5,6].