It has been proposed in ccRCC that, following a VHL mutation, one copy of 3p is deleted and that the other genes are ‘opportunistic’ in that they can act as tumour suppressors, while only requiring a single ‘hit’, because they have been rendered hemizygous by the VHL ‘second hit’ (summarized in ref. 39). This evidence concerns the gene VHL and nonpapillary renal cell carcinoma.