While it is likely that HIF-1α regulates many cellular processes that are important for tumour initiation and development, our previous observation that deletion of Hif1a prevents the formation of cysts and tumours in Vhl/Trp53 mutant mice provides at least correlative evidence that is consistent with the notion that this early vascularization is important for the initiation of ccRCCs. Here, HIF1A is linked to neoplasm.