There was a higher incidence of genetic discordance between primary and metastatic site samples in patients harbouring mutations within the SETD2 (SET domain containing 2, histone lysine methyltransferase) gene, suggesting that this gene may regulate the rate of genetic variation within RCC cells enabling the generation of cell lines harbouring pro-metastatic mutations [39]. The gene discussed is SETD2; the disease is renal cell carcinoma.