VHL and neoplasm: The VHL protein (pVHL) regulates hypoxia-inducible factor (HIF) by ubiquitin-mediated destruction [26,27] and in the absence of functional pVHL, HIF activates a number of hypoxiaresponse genes such as vascular endothelial growth factor (VEGF), erythropoietin (Epo), platelet derived growth factor (PDGF), TFG-α and -β, all of which are associated with tumour angiogenesis and growth [28-30].